3 letters:
ein

4 letters:
dine, fein, fine, hein, hine, jain, kyne, line, lyne, mine, nine, pine, pyne, rine, sein, sign, sine, tine, tyne, vine, wine, wyne, zine

5 letters:
9a-91, 9nine, aisne, align, aline, ayein, brein, brine, bryne, cline, clyne, crine, dhein, drein, dwine, feine, feyen, ghain, grine, guynn, gwine, heine, heyen, huynh, k-391, klein, kline, lysne, m1151, olein, opine, prine, pruyn, pt-91, quine, rhein, rhine, rhyne, seyen, shein, shine, shyne, spine, spyne, stein, stine, styne, swine, thein, thine, trein, trine, twine, vf-51, whine, wz551, yj-91

6 letters:
-cline, a-line, aedine, affine, alkine, alline, alpine, alvine, alwine, arline, arlyne, ashine, assign, axline, b-line, benign, bobine, bovine, byline, canine, cosign, define, design, devine, dewine, didine, divine, dynein, equine, extine, feline, fokine, gaz-51, gemein, hauyne, hinein, infine, inline, intein, iodine, k-line, kleine, komine, l129a1, lawine, levine, limine, lupine, lutein, malign, mutein, nadein, obsign, ondine, online, orcein, park51, rapine, rd-191, refine, reline, resign, rheine, s-mine, schein, scrine, sejein, shrine, spline, steine, strine, supine, theine, tobine, tunein, tvline, unline, upline, v-sign, v/line, v sign, wz-551

7 letters:
.online, adeline, airline, akamine, alamein, alewine, amrhein, anodyne, antwine, archine, area 51, arnwine, arshine, ashline, asinine, beguine, beltein, beshine, brucine, burdine, by-line, c10h15n, calcein, calpine, carbine, carline, catline, chopine, co-sign, colline, combine, condign, confine, consign, cutline, cyanine, darline, decline, dieline, dyeline, eadwine, eiswein, elapine, emeline, emlynne, entwine, eponine, epstein, erskine, frulein, gallein, gardyne, genuine, geodyne, godwine, gumline, gutwein, hallein, hautein, helvine, hemline, henline, hipline, hopbine, hopvine, hotline, huffine, icewine, idstein, in-line, incline, insigne, intwine, in line, iresine, jardine, jazmine, kantine, karline, layline, leonine, leukine, lignine, logline, logmein, louvine, mallein, marline, mauvine, medline, melvine, midkine, midline, milvine, mullein, mundine, myeline, myokine, nalline, offline, oldline, on-line, outline, oxidyne, pathein, paytine, peavine, potline, prefine, proline, prosign, qbz-191, quinine, ralline, ramline, rankine, ratline, re-sign, realign, realine, recline, redline, redmine, redwine, rn cine, romeine, rotwein, schlein, schwein, sealine, setline, skyline, sollein, stibine, stikine, subline, subsign, sylvine, tagline, tipline, topline, untwine, up-line, vandine, vanduyn, vandyne, villein, vulpine, zipline

8 letters:
acridine, acronine, actodine, aerodyne, agmatine, air-line, alcidine, alkaline, amandine, ampakine, andesine, angelyne, apolline, arginine, atropine, autodyne, b-spline, backline, balkline, bar line, baseline, bassline, bee-line, beltline, berkline, bistline, blondine, blueline, bodyline, buntline, bustline, bus line, byerlein, calamine, callsign, cameline, capeline, careline, caroline, cathrine, catiline, ceradyne, cerulein, champine, charlyne, chatline, ciconine, codesign, columbin, consigne, contline, coraline, coridine, cuthwine, cytidine, cytokine, daidzein, dateline, day-fine, deadline, delphyne, digidyne, docusign, downline, dragline, dropline, duvetyne, eberlein, eberwein, ecgonine, eckstein, ecocline, emmeline, enshrine, etheline, eugubine, exocrine, eyeshine, feedline, fireline, firesign, fishbein, fishline, flatline, fordwine, francyne, fraulein, gag line, galatine, gantline, gas line, germline, ginuwine, girtline, gluhwein, goeglein, goldfine, goldline, goldmine, goodwine, gorsline, gourdine, gralline, grandine, grumbine, hainline, hairline, handline, haneline, hardline, hartline, headline, heinlein, helpline, hematein, heublein, highline, hineline, hirudine, holstine, hominine, homodyne, hot-line, hot line, ice-nine, inshrine, jacobine, jug wine, karoline, kathline, kichline, landline, landmine, landwein, lateline, lazuline, leontine, lga 1151, lifeline, lipstein, log line, longline, loveline, loxapine, lupinine, lustrine, mainline, mauveine, may wine, mcalpine, megadyne, mifegyne, milstein, misalign, moelline, monokine, moulmein, nearline, neckline, neustine, new line, nonalign, nut pine, off-line, old-line, one-line, orgotein, oscinine, outshine, outtwine, ovaltine, overline, palatine, papyrine, paradyne, pavonine, pinoline, pipeline, pipevine, plotline, polyline, popeline, portwein, prochein, pyridine, pyronine, qraspine, ramstein, re-align, reassign, redefine, redesign, red line, red pine, red wine, resupine, richwine, ricinine, rockline, roofline, roseline, rubidine, rutstein, shampine, sharline, shinbein, sideline, slimline, snapline, songline, sourdine, soverign, stanline, sturnine, suilline, sunshine, surfline, susswein, sycamine, t-online, t-spline, tag line, tapeline, tarwhine, teledyne, teradyne, teredine, thalline, theanine, thionine, tideline, top-line, tramline, trapline, treeline, triolein, trotline, two-line, tyramine, unbenign, undefine, undivine, vanduyne, viridine, wetstein, wickline, widevine, wireline, withvine, withwine, woodbine, woolwine, xylidine, yardline, yoyodyne, zibeline, zip-line, zumstein

9 letters:
9lokknine, aashayein, acesodyne, aconitine, allgemein, almandine, almondine, amanitine, amoxapine, amplidyne, anticline, apfelwein, aronstein, back-line, baicalein, bali nine, bank line, barentine, beachline, benzidine, bergstein, berylline, betonline, bildstein, bizantine, bloodline, bluestine, body-line, boehnlein, bordstein, bornstein, brandwein, brasilein, brazilein, breadline, bronstein, brookline, bull pine, burnstein, byzantine, by design, caerulein, calixtine, carnitine, catchline, celandine, cheerwine, chemokine, childline, chow line, cinnamein, cisalpine, city line, clozapine, coastline, collidine, columbine, compudyne, concubine, conradine, considine, coralline, cordyline, corolline, covelline, crestline, crossline, crossnine, cymbeline, date line, decdesign, drinkwine, driveline, drop line, earlywine, echidnine, econoline, edelstein, eglantine, emoxypine, endocrine, enterline, erythrine, escharine, esterline, falconine, faultline, fedelline, feinstein, fendiline, fierstein, fischbein, foul line, friedline, fromstein, frontline, frostline, fuel line, gigantine, gladstein, glafenine, goal line, goldstein, goodstein, grapevine, graveline, grinstein, grubstein, guideline, haematein, half-line, halocline, hand line, hard-line, hartstein, hazeltine, heberlein, helicline, herakline, heseltine, high sign, hirundine, hoop pine, hornstein, houseline, hyperfine, incombine, indecline, indochine, interdyne, interline, intestine, intextine, jack pine, jade vine, jaqueline, jennewein, josceline, joscelyne, kairoline, kaleerein, kiwi vine, l-proline, laburnine, lampyrine, land mine, lardacein, laughline, lead line, legantine, levantine, life line, load line, loop-line, love line, love vine, lurchline, macalpine, main-line, main line, manueline, maudeline, memantine, merocrine, metalline, metroline, microdyne, millstein, misassign, moleskine, moneyline, moonshine, multiline, mundelein, nepheline, nickeline, nightline, non-align, normodyne, noscapine, nothstein, orpheline, overshine, ovibovine, palestine, pargyline, pascaline, pempidine, pericline, pethidine, pettywhin, pieridine, pink wine, pipe-line, pipe vine, plot line, plumbline, plus sign, polyamine, pond pine, porcelein, porcupine, port wine, post-fine, powerline, predefine, predesign, presteign, priceline, primuline, protopine, punchline, pyrroline, rail line, recombine, reconsign, reichwein, reinstein, rhodanine, ridgeline, rootstein, rose wine, saberbein, salt mine, sandstein, sash line, saturnine, saturnyne, scopeline, scoreline, secundine, sensodyne, serrefine, shoeshine, shoreline, sibylline, sightline, silkaline, silk vine, snow-line, snow line, sparkline, stanadyne, starshine, stecklein, storyline, strapline, subalpine, subdivine, succubine, superfine, sympathin, tafelwein, tara vine, threonine, thyronine, time-line, toll line, toluidine, totaquine, touchline, trainline, trap line, trautwein, tree-line, tree line, trendline, tres-tine, tres-tyne, trimedyne, trip line, tropidine, troutwine, truckline, true pine, trunkline, twonshein, underline, undermine, undersign, valentine, vanilline, vase-fine, vase vine, vincamine, vitelline, waistline, waldstein, waterline, webassign, weinstein, wendeline, worldline, yohimbine

10 letters:
aberdevine, adamantine, agate line, alabandine, allgemeine, alpestrine, altar wine, anopheline, antilopine, antipyrine, arecaidine, asselstine, avengelyne, ballantine, bankverein, barkantine, barkentine, barrentine, baulk-line, black pine, blood line, blush wine, bodenstein, borderline, borenstein, brabantine, brandywine, branntwein, braunstein, bread line, brigandine, brightline, brillstein, brisendine, brownstein, brown pine, butenafine, canavanine, capitoline, capreoline, casterline, centerline, chalk line, chemdesign, cheventein, chile pine, chinoidine, chlorodyne, cinchonine, citrulline, cladribine, clemastine, clementine, clorgyline, clotiapine, cloud nine, color line, conga line, conquinine, coppermine, coral vine, creatinine, cross vine, cryptopine, dapoxetine, dealerline, delay line, desmoglein, dipyridine, disentwine, disincline, dragantine, drive line, duberstein, duloxetine, dyphylline, earthshine, el alamein, envirodyne, ergonovine, ergotinine, evangeline, famotidine, fault line, fence line, feuerstein, field line, fifty-nine, first-line, fluoxetine, foredesign, forty-nine, front-line, front line, geldschein, get a line, gillentine, gismondine, glickstein, globalsign, gnoscopine, goberstein, gourd vine, greenstein, haloxyline, healthdyne, healthline, heart line, heterodyne, image-line, imipramine, interligne, intertwine, isabelline, isocyanine, italdesign, ivabradine, john prine, juglandine, kudzu vine, l-arginine, lanthopine, laugh line, leger line, lowenstein, lymphokine, m1 carbine, m4 carbine, mailonline, melon vine, meperidine, mephaquine, methionine, microcline, minus sign, misincline, missildine, mondschein, mujahadein, necroshine, neurocrine, nicotidine, night-line, olanzapine, one-design, overrefine, party line, pearlstein, pearlstine, pentaquine, pepperdine, persantine, pfundstein, pholcodine, phone line, piperidine, pitch pine, pizotyline, playonline, plumb-line, plumb line, porpentine, power line, preconsign, primaquine, prometryne, punch line, pyrazoline, pyrethrine, pyroxyline, quetiapine, ranitidine, reboxetine, reynardine, rheinstein, rhine wine, rhone wine, ricinolein, ridge-line, river tyne, rivet line, rocketdyne, rosenshine, rosenstein, royal line, rubinstein, rudenstine, rupestrine, saccharine, scallopine, scots pine, screw pine, scrub pine, semidivine, serpentine, sertraline, sewer line, sharp-sign, shore pine, short line, silvervine, sixty-nine, smaragdine, smithkline, staff line, staff vine, state line, steam line, stoecklein, stone pine, strandline, straw wine, streamline, strip-mine, strip mine, strychnine, swamp pine, swiss pine, table wine, technodyne, terpentine, three-line, timberline, touch-line, traunstein, trend line, tridentine, triphyline, trunk line, turnverein, turpentine, vanalstyne, verse line, vogelstein, water line, white line, white pine, white wine, windradyne, world-line, zidovudine, zollverein

11 letters:
#pound-sign, #sharp-sign, adam devine, alabastrine, amidopyrine, aminopyrine, amodiaquine, antalkaline, atomoxetine, barquentine, bartlestein, battle line, benztropine, bicuculline, bishop pine, boomershine, bottom-line, bottom line, branch line, brillantine, canary wine, celery pine, center line, chloriodine, chloroquine, cholophaein, chorus line, chrysoidine, constantine, cooperstein, copper mine, countermine, countersign, county line, credit line, crystalline, danger line, desipramine, dianisidine, dicyclomine, dizocilpine, dobberstein, dollar sign, draw a line, drop a line, dunfermline, eighty-nine, emisunshine, equals sign, erythrolein, ethacridine, family line, feeder line, finish line, finkelstein, firing line, flight line, fluorescein, fringilline, geanticline, goldenstein, grabenstein, ground pine, grudenstein, haemaphaein, hammerstein, hartenstein, heterocrine, hexobendine, homatropine, iodoquinine, isoxsuprine, jersey pine, kevin kline, knotty pine, kornerupine, l-carnitine, ledger line, limber pine, lisofylline, lofepramine, lubber line, maprotiline, marine mine, mirtazapine, mitragynine, mohabbatein, monkeyshine, mulled wine, muscicapine, musikverein, neostigmine, nine-o-nine, ninety-nine, oregon pine, over-refine, p-anisidine, peanut vine, pepper vine, phalloidine, phenacetine, picket line, planet nine, potato vine, pyrrolidine, quartervine, radioiodine, randfontein, ringvereine, sabine pine, safferstein, scotch pine, silberstein, silverstein, silver mine, silver pine, silver vine, spectradyne, spruce pine, squall line, squash vine, static line, street sign, string line, supply line, swainsonine, terbinafine, thermocline, the farm 51, thirty-nine, throughline, ticket line, ticlopidine, timber line, tolterodine, torrey pine, towing line, transalpine, tranzalpine, tree lupine, trimebutine, trochantine, twenty-nine, veratridine, vinorelbine, voestalpine, wallenstein, wallerstein, wasserstein, wildschwein, wild lupine, winterstein, yellow pine, zach lavine

12 letters:
aber-de-vine, actor's line, ancient pine, azathioprine, balloon vine, benzatropine, bloemfontein, bob einstein, brandenstein, brilliantine, bulbocapnine, clomipramine, command-line, command line, contour line, cypress-pine, cypress pine, cypress vine, dessert wine, douglas pine, eticyclidine, externsteine, fall in line, false lupine, fenethylline, field lupine, fishing line, fleckenstein, frankenstein, gastrophryne, georgia pine, grootfontein, guanethidine, harpoon line, hazel irvine, hickory pine, hydrastinine, intercolline, isoquinoline, jeffrey pine, kraaifontein, lateral line, leintwardine, lichtenstein, liothyronine, maginot line, melodic line, mooring line, nasopalatine, observantine, oil pipeline, opening line, oxyquinoline, percent sign, phycophaeine, postpalatine, poverty line, prickly pine, private line, procyclidine, product line, program line, pumpkin vine, quarter-vine, radical sign, railway line, rivastigmine, running pine, russian vine, saccharopine, seventy-nine, shoot a line, soledad pine, stepped line, sterkfontein, stolperstein, struthionine, sulphur mine, surface-mine, surface mine, theophylline, toe the line, transit line, trigonelline, trimipramine, trolley line, trumpet vine, vortioxetine, waiting line, white lupine, wild quinine, windows-1251, zooerythrine

13 letters:
akani simbine, albion online, amifampridine, aminophylline, arctic-alpine, assembly-line, assembly line, babinski sign, bishop's pine, bob weinstein, boeschenstein, bordeaux wine, boundary line, buntsandstein, burgundy wine, business line, chelerythrine, chlorhexidine, cinnamon vine, colestyramine, cucumber vine, cystathionine, deoxycytidine, district line, dividing line, draw the line, dryopithecine, etonitazepyne, floating mine, geodesic line, goa bean vine, hold the line, hylactophryne, iodothyronine, labiopalatine, levocarnitine, liechtenstein, loblolly pine, longleaf pine, magnetic mine, methantheline, monterey pine, mountain pine, naphthalidine, normeperidine, occultic;nine, perivitelline, phencyclidine, phenoperidine, physostigmine, prince's pine, princess pine, propantheline, property line, pseudouridine, railroad line, railroad vine, schottenstein, sounding line, spectrum line, spreadthesign, spurling-line, starting line, straight-line, straight line, sulfapyridine, transpalatine, twyfelfontein, umbrella pine, virginia pine, westland pine, weymouth pine, wine and dine, yellow lupine

14 letters:
above-the-line, adobe indesign, allegheny vine, azidothymidine, beta-carboline, blue columbine, bret weinstein, cholestyramine, count palatine, eric weinstein, fahrenheit 451, finishing line, fortified wine, groundnut vine, hexactinelline, hexadimethrine, hydroxyproline, idar-oberstein, jeffrey's pine, less-than sign, lodgepole pine, markina-xemein, matrimony vine, matthew modine, neuroendocrine, nissan skyline, noncrystalline, pentoxifylline, phenanthridine, phenanthroline, phil valentine, phthalocyanine, ponderosa pine, pyridostigmine, reception line, scrimmage line, siegfried line, sparkling wine, sphenopalatine, steamship line, subcrystalline, sulphapyridine, sundial lupine, telegraph line, telephone line, tree celandine

15 letters:
4-aminopyridine, acetylcarnitine, australian pine, benzoylecgonine, california wine, cantaloupe vine, carolina lupine, celery top pine, county palatine, dideoxycytidine, dihydropyridine, egyptian lupine, ehrenbreitstein, glaxosmithkline, hanoverian line, hemicrystalline, holocrystalline, hypocrystalline, interior design, lay on the line, monocrystalline, paddy considine, percentage sign, phenazopyridine, polycrystalline, povidone-iodine, production line, pterygopalatine, put on the line, regression line, run-of-the-mine, semicrystalline, spirits of wine, superheterodyne, top-of-the-line, top of the line, vespertilionine, watermelon vine, white star line

16 letters:
alaskan pipeline, be on cloud nine, canada porcupine, demarcation line, easter lily vine, guinea gold vine, harvey weinstein, intercrystalline, lancastrian line, lesser celandine, maxillo-palatine, methylergonovine, mexican nut pine, microcrystalline, moreton bay pine, multicrystalline, n-methyltyramine, pharyngopalatine, phosphothreonine, protocrystalline, red cypress pine, running headline, ship of the line, silver lace vine, sonic delay line, sweet melon vine, swiss stone pine, sword art online, triiodothyronine, wild potato vine

17 letters:
ashton-under-lyne, australopithecine, canadian red pine, china fleece vine, common grape vine, cryptocrystalline, european nut pine, frankincense pine, greater-than sign, greater celandine, indian rupee sign, japanese red pine, keith silverstein, king william pine, oil of turpentine, port jackson pine, psitta-co-fulvine, sweet potato vine, tasman dwarf pine, transmission line, tri-iodothyronine, unemployment line, white potato vine, winter melon vine

18 letters:
acetyl-l-carnitine, alpine celery pine, automobiles alpine, black cypress pine, brooklyn nine-nine, common sickle pine, eastern white pine, equity credit line, newspaper headline, phanerocrystalline, prairie gourd vine, robert a. heinlein, state of palestine, summer squash vine, tetraiodothyronine, textile screw pine, tincture of iodine, triphosphopyridine, western white pine, white cypress pine

19 letters:
acoustic delay line, american white pine, black desert online, dwarf mountain pine, japanese black pine, japanese table pine, mandatory palestine, newcastle-upon-tyne, new caledonian pine, new world porcupine, norfolk island pine, northern pitch pine, old world porcupine, swiss mountain pine, ufc fight night 191, uruguay potato vine, western yellow pine

20 letters:
7-hydroxymitragynine, 8-chlorotheophylline, domain-driven design, mason and dixon line, personal credit line, southern yellow pine, spirit of turpentine, ursula von der leyen

21 letters:
common matrimony vine, computer-aided design, olanzapine/fluoxetine, sierra lodgepole pine, western prince's pine

22 letters:
japanese umbrella pine, mason and dixon's line, new zealand white pine, omega-n-methylarginine, wild sweet potato vine

23 letters:
4-dimethylaminopyridine, bullet for my valentine, federal charter of 1291, grand theft auto online, international date line, last of the summer wine, southwestern white pine, willard van orman quine

24 letters:
capital of liechtenstein, the elder scrolls online

25 letters:
new zealand mountain pine

26 letters:
electromagnetic delay line

27 letters:
second battle of el alamein

28 letters:
american airlines flight 191, massively multiplayer online

8 letters:
aquiline

9 letters:
macedoine