2 letters:
ek

3 letters:
bec, dec, eck, lek, nec, rec, sec, tec, tek

4 letters:
apec, atek, baek, beck, cech, chek, dech, deck, exec, feck, geck, heck, itek, jech, keck, lech, leck, mech, meck, neck, opec, pech, peck, quek, rech, reck, seck, shek, spec, stec, svec, tech, teck, trek, weck, wnek, yeck, zech, zeck

5 letters:
.tech, adtec, aleck, altec, amdec, amtec, antec, ardec, artek, aspec, astec, aztec, baeck, berec, blech, bleck, bocek, botec, bovec, brech, breck, cetec, ce ec, check, cimec, cleck, codec, czech, deque, detec, dreck, dweck, edhec, emtec, endec, entec, erech, espec, essec, estec, etech, fc ec, fleck, frech, freck, gacek, grech, gtech, hacek, hecke, hitec, hrbek, huvec, indec, intec, isrec, itech, itsec, jacek, kexec, kleck, kneck, konec, kotek, krech, lecke, macek, magec, mitek, mivec, mtech, nadec, nobec, notec, novec, oapec, optek, oreck, ossec, petek, ptech, rebec, repec, rexec, rspec, satec, seche, seque, setec, sheck, shrek, sidek, sneck, spech, speck, stech, steck, tekke, treck, tucek, utech, vacek, vanek, vtech, wreck, yecch, yekke, zacek, zadek, zebec, zecke, zweck

6 letters:
a4tech, adtech, afotec, agetec, ametek, amtech, anitec, apobec, apotek, aptech, armtec, armtek, asetek, autech, bartek, bedeck, bestek, bistec, bobeck, brekke, ceatec, cheque, coltec, comtec, creque, crytek, dehecq, deltec, destec, ditech, domecq, dubcek, ecotec, edtech, eotech, evotec, fanech, fecche, gatech, geotek, hi-tek, hitech, howtek, hw lec, imtech, inspec, intech, kretek, labtec, lamech, lectec, lovech, lubeck, lybeck, martek, mastec, mcpeck, mecque, melech, memtec, mestek, mixtec, moftec, molech, mrotek, navteq, nectec, newtek, nortec, nortek, parsec, photek, piapec, placek, plocek, portec, protec, prypec, ptacek, quakec, quebec, ramtek, recche, refseq, robeck, rubeck, scatec, scheck, secque, shreck, siltec, simtek, sobeck, sovtek, strech, streck, syntec, tanrec, tenrec, theque, toltec, unitec, unitek, uttech, v-neck, valtek, varech, vortec, wabtec, weitek, wfq ec, winhec, zentec, zyrtec

7 letters:
abcotek, adaptec, airmech, banacek, banctec, biotech, bishkek, bluetec, bo-shek, bombeck, brintec, brobeck, brubeck, bruneck, caltech, chameck, comptek, comspec, comtech, cytotec, dembeck, digitek, dilbeck, dombeck, drecche, epitech, equitec, eyetech, femtech, fintech, francek, fujitec, gleevec, goertek, grecque, harbeck, hemotec, henpeck, hi-tech, huastec, icohtec, indotec, isoetec, kel-tec, kominek, konicek, liberec, limbeck, lo-tech, luebeck, manbeck, martech, maybeck, mazatec, memotec, milspec, miratec, mpe fec, nyentek, oobleck, pantech, pentech, pipetec, positec, postech, raytech, realtek, recheck, redneck, rna-seq, schleck, schmeck, schneck, schreck, scitech, seebeck, semtech, seq2seq, showtek, sinopec, softech, solitec, srimech, stantec, strecke, sudbeck, syntech, szczech, teaneck, thortec, transec, uisnech, uncheck, vasotec, ventech, viratek, vo-tech, vojtech, wavetek, wedtech, whinsec, witbeck, wozzeck, wrecche, wryneck, yucatec, zaitech, zapotec

8 letters:
aerotech, aircheck, alt-tech, aristech, asiatech, atac-seq, autoexec, averbeck, big tech, bio-tech, biontech, birkbeck, blendtec, boltneck, brodbeck, bullneck, cargotec, chaneque, chemtrec, clauneck, convatec, coorstek, coretech, cppcheck, crewneck, cromlech, cryptrec, cytotech, desertec, digitech, dynatech, ewe-neck, filespec, fishbeck, flyspeck, foredeck, gladbeck, goldbeck, golombek, gonothec, gun deck, hatcheck, hen-peck, hightech, holodeck, hornbeck, infotech, intertek, intratec, inventec, investec, in check, kennebec, kermadec, kohlbeck, kompanek, kumrovec, lithtech, logitech, longneck, low-tech, lundbeck, magnetek, meditech, merovech, microtek, mil-spec, minntech, nanotech, overbeck, overpeck, pathspec, paycheck, peremech, philbeck, plambeck, playtech, polartec, polytech, presstek, prestech, questech, raisbeck, rechteck, reznicek, ringneck, robotech, rollneck, sam quek, schnecke, sematech, sir-tech, spartech, sun deck, symantec, ticketek, trellech, triotech, vanhecke, vanvleck, vocaltec, vulfpeck, welltech, westtech, whitbeck, woodbeck, woodpeck, word2vec, wordtech

9 letters:
abimelech, afterdeck, aggrotech, ahimelech, ameritech, anandtech, aquidneck, astrotech, backblech, backcheck, bad check, bed check, beef neck, bell deck, boat deck, bodycheck, breakneck, bull neck, cleantech, cognitech, coincheck, crew-neck, crew neck, crookneck, dailytech, deer-neck, elimelech, eurocheck, filtertek, forecheck, funcinpec, gendrisek, genentech, half-deck, high-tech, hilsabeck, hybritech, intertech, jeff beck, labrecque, main deck, mnase-seq, namecheck, nano-tech, nescopeck, overcheck, pinchbeck, polo-neck, poop deck, publitech, raincheck, receptech, rhinebeck, ring-neck, rosenbeck, roughneck, sabertech, sabortech, sabretech, steenbeck, steinbeck, strombeck, tape deck, telecheck, terratech, trolltech, vaccitech

10 letters:
achimelech, anammelech, attoparsec, back-check, bank check, battletech, body-check, bottleneck, burghbrech, cargo deck, crosscheck, dillenbeck, eurocheque, fiddleneck, fore-check, ghettotech, hallenbeck, halterneck, hollenbeck, immunetech, kaisertech, kiloparsec, libavcodec, limberneck, littleneck, lower deck, megaparsec, muscletech, pinakothek, poke-check, poke check, quickcheck, rain check, rubberneck, schoenbeck, scoop-neck, scott beck, spellcheck, spot-check, steam deck, storagetek, tabachneck, third deck, tlaxcaltec, triple sec, tschakmeck, turtleneck, upper deck, vanderbeck, westerbeck

11 letters:
adrammelech, amy yasbeck, awning deck, blank check, bottle-neck, bridge deck, chapultepec, cross-check, cthulhutech, discotheque, doublecheck, extremetech, fk jablonec, flight deck, fourth deck, heuschrecke, killingbeck, leatherneck, quarterdeck, second deck, shadow.tech, spell-check, tehuantepec, world-check

12 letters:
bibliotheque, cinematheque, countercheck, double-check, health check, hit the deck, landing deck, parity check, regem-melech, shelter deck, weather deck

13 letters:
cassette deck, hunt-and-peck, panzerschreck, payroll check, pontiac aztek, richard speck

14 letters:
banker's check, hurricane deck, medicare check, personal check, promenade deck

15 letters:
cashier's check, certified check, chiang kai-shek, christophe beck, redundant check, sinovac biotech

16 letters:
attendance check, disability check, discovered check, pain in the neck, retirement check, toulouse-lautrec, traveler's check

17 letters:
treasurer's check

21 letters:
standard 52-card deck, timeline of star trek

22 letters:
rider-waite tarot deck

25 letters:
henri de toulouse-lautrec