3 letters:
ord

4 letters:
cord, ford, hord, lord, mord, nord, ward

5 letters:
abord, acord, avord, award, borde, bored, chord, coard, coord, corde, cored, fjord, fnord, foard, forde, goard, gored, gourd, hoard, horde, jorde, lorde, lourd, m-84d, morde, njord, nored, oared, opord, pored, soard, sored, sourd, stord, sward, sword, thord, warde

6 letters:
-oared, aboard, accord, acorde, adored, afford, akkord, alvord, axford, belord, chord-, chored, dabord, debord, disord, doored, dubord, gboard, gourde, hoared, lourde, mccord, milord, navord, norred, poured, record, rekord, remord, revord, reward, roared, scored, shored, snored, soared, sourde, spored, stored, toward, unlord, whored, xboard

7 letters:
-doored, analord, balourd, bichord, bitlord, bojnord, concord, daccord, deborde, dichord, encored, floored, gaylord, gunlord, ignored, inboard, laborde, leapord, mainord, misword, onboard, plourde, reboard, seabord, shavord, teaford, ungored, unhoard, uphoard, urocord, warlord

8 letters:
abhorred, amarcord, backbord, beauford, borgward, boxboard, chambord, concoord, concorde, deplored, druglord, ex-board, explored, flyboard, funboard, garboard, implored, jamboard, julebord, kanboard, keyboard, landlord, lapboard, larboard, leeboard, limfjord, lustmord, montford, mopboard, on-board, outboard, overlord, palourde, pegboard, perigord, pinboard, plyboard, postnord, preboard, randlord, rerecord, restored, seaboard, skiboard, skyboard, slumlord, tagboard, tipsword, toeboard, trichord, unmoored, untoward, urochord, vapoured, verwoerd, webboard, woodward

9 letters:
balisword, baseboard, billboard, bodyboard, brantford, brentford, buckboard, callboard, cardboard, chipboard, clapboard, clipboard, corkboard, dartboard, dashboard, decachord, disaccord, duckboard, fallboard, fireboard, flipboard, foilboard, footboard, formboard, freeboard, fretboard, gameboard, gangboard, gravikord, hardboard, headboard, hexachord, highboard, hitrecord, kickboard, kneeboard, longboard, lysefjord, mainboard, manichord, millboard, moldboard, monochord, mountford, neurocord, notochord, octachord, off-board, offshored, omnichord, openboard, oslofjord, outpoured, outscored, overboard, peg-board, perfboard, plugboard, polychord, prerecord, pulpboard, re-record, rheochord, sailboard, sandboard, shipboard, shopboard, sideboard, signboard, skimboard, slipboard, snowboard, star-lord, stowboard, surfboard, tailboard, talkboard, vassalord, veroboard, wakeboard, wallboard, washboard, workboard

10 letters:
aboveboard, anemochord, applyboard, bangalored, bargeboard, blackboard, blockboard, boknafjord, bon-accord, breadboard, broadsword, call-board, chalkboard, chessboard, clarichord, clavichord, dash-board, drainboard, earthboard, elbowboard, fall-board, fiberboard, fibreboard, flakeboard, flashboard, floorboard, flushboard, guideboard, hafrsfjord, half-board, half-sword, heptachord, hoverboard, imageboard, knifeboard, linerboard, liveaboard, long-sword, matchboard, mouldboard, needlecord, notchboard, panelboard, paperboard, pargeboard, pasteboard, patchboard, pedalboard, pentachord, pressboard, punchboard, sandefjord, scaleboard, scoreboard, scrubboard, selbstmord, shortboard, shortsword, shoveboard, side-sword, sign-board, skateboard, snakeboard, sognefjord, soundboard, sprayboard, starrboard, stevedored, storyboard, strawboard, stripboard, superboard, tetrachord, treadboard, underboard, unexplored, unimplored, unrestored, vergeboard, wasteboard, waterboard, weaponlord, weighboard, whiteboard, witchboard, word-hoard, work-board

11 letters:
above-board, beagleboard, beaverboard, bridgeboard, centerboard, centreboard, cheeseboard, cradleboard, daggerboard, fingerboard, flekkefjord, harpsichord, leaderboard, misericorde, motherboard, noticeboard, paddleboard, posterboard, shovelboard, silversword, smorgasbord, sound-board, splashboard, sportaccord, springboard, stringboard, switchboard, systemboard, tape-record, teeterboard, toetsenbord, underscored

12 letters:
checkerboard, chequerboard, clapperboard, draughtboard, flannelboard, flutterboard, hamburg-nord, harmonichord, mortar-board, plasterboard, scraperboard, scratchboard, shovel-board, shuffleboard, terpsichorde, underinsured, weatherboard

13 letters:
cavalry-sword, cotes-du-nord, daughterboard, montreal-nord, on-the-record, particleboard, shuffle-board, weather-board

14 letters:
containerboard, geirangerfjord, hardangerfjord, off-the-record, sounding-board

16 letters:
across-the-board

4 letters:
card, bard, nerd, curd, herd, word, bird, nard, gird, hard, byrd, yard, lard, hurd

5 letters:
laird, beard, weird, cared, dared, lured, guard, third, eared, chard, mired, sherd, wired, aired, cured, heard, shard, bared, baird, fared

6 letters:
burred, furred, absurd, geared, inured, regard, barred, stared, begird, spared, paired, haired, marred, retard, canard, shared, scared, reword, feared, afeard, flared, gerard, tabard, toured

7 letters:
unheard, scarred, discard, matured, revered, bombard, charred, blurred, expired, slurred, attired, stirred, endured, sheared, bernard, afeared, assured, spurred, smeared, secured, cleared, squared, starred, retired, chaired, insured, cheered, there'd, unaired, uncured, where'd

8 letters:
impaired, declared, required, unbarred, unpaired, incurred, laboured, appeared, interred, prepared, repaired, referred, deferred, compared, deterred, obscured, occurred, ungeared, unmarred, unshared

9 letters:
reassured, preferred, uninsured, unsecured, conferred, overheard, disregard, besmeared, dog-eared, langobard, longbeard, off-guard, one-third, pioneered, unattired, uncleared, undergird, unsheared, unstarred

10 letters:
undeclared, unprepared, unimpaired, undeterred, blackbeard, camelopard, engineered, goatsbeard, interfered, salt-cured, unrepaired

11 letters:
disappeared, avant-garde, volunteered, transferred, back-geared, ill-starred, quick-eared, sharp-eared, smoke-cured

12 letters:
light-haired, self-assured, twenty-third

13 letters:
double-geared

16 letters:
hearing-impaired