3 letters:
ard

4 letters:
bard, blvd, card, gard, hard, lard, nard

5 letters:
alard, baard, barde, byard, carde, chard, erard, garde, giard, guard, huard, icard, k-svd, mocvd, paard, parde, phard, sarde, scard, shard, suard, tarde, varde, vcard, waard, yarde

6 letters:
asgard, barred, bedard, benard, berard, bevard, bovard, boyard, bozard, busard, buzard, canard, charde, decard, denard, dinard, e-card, eckard, edvard, enlard, fayard, fugard, garard, garred, gerard, girard, godard, homard, hucard, jarred, lazard, legard, marred, mccard, menard, minard, mulard, musard, p-card, parred, picard, regard, renard, retard, revard, ricard, rocard, tabard, tarred, upcard, utgard, waarde, warred, zwaard

7 letters:
-barred, adguard, agobard, aircard, amtgard, archard, barnard, beghard, beguard, belgard, bellard, bernard, berrard, billard, blafard, boilard, bolyard, bombard, bongard, bossard, brocard, bunyard, burnard, charred, chocard, cobarde, cocarde, damgard, deckard, dennard, dewaard, diehard, dillard, discard, eckhard, einhard, enguard, esguard, gabbard, gallard, gaspard, geghard, gelbard, gerhard, gibbard, gillard, gilyard, ginyard, giscard, gnarred, gossard, guerard, hilyard, hopyard, innyard, jarrard, keycard, leotard, mullard, newhard, ni-hard, np-hard, panhard, piccard, pickard, poulard, rennard, rutgard, scarred, sinyard, sparred, starred, suchard, sungard, suscard, unguard

8 letters:
armguard, backyard, bankcard, barnhard, barnyard, blancard, blowhard, boatyard, bombarde, boneyard, borchard, bouchard, bouffard, brancard, brochard, bromyard, brossard, burchard, cashcard, datacard, debarred, deeryard, dockyard, dooryard, drawcard, dungyard, ekkehard, embarred, eurocard, farmyard, fauchard, filecard, foreyard, glowbard, grignard, grognard, guichard, guinyard, guiscard, hillyard, hortyard, isengard, isracard, jackyard, jacquard, julliard, junkyard, kailyard, kaleyard, kirkyard, lienhard, maillard, mansarde, marquard, meinhard, melgaard, metacard, meteyard, mouchard, moutarde, mudguard, notecard, outguard, overcard, pericard, postcard, racecard, railcard, railyard, reinhard, safecard, semihard, shipyard, shurgard, telecard, tiltyard, timecard, tonocard, unbarred, valeyard, vanguard, vuillard, whinyard, wildcard, willyard, wirecard, woodyard, zinecard

9 letters:
adenocard, appleyard, bestarred, blow-hard, bodyguard, boucharde, bouffarde, boulevard, brickyard, broussard, cabochard, chauffard, chouinard, colombard, costarred, couillard, coulthard, courtyard, dai-guard, disbarred, disregard, engelhard, fireguard, fishguard, flashcard, graveyard, greencard, grossbard, hildegard, hypercard, instarred, langobard, lifeguard, longobard, metrocard, microcard, milliarde, misregard, moneycard, newsguard, noseguard, off-guard, overgaard, phonecard, pickguard, pockarred, punchcard, rearguard, rock-hard, rouillard, safeguard, scorecard, scrapyard, shinguard, smartcard, stackyard, steelyard, stockyard, studtgard, telengard, tilt-yard, undercard, unscarred, unstarred, videocard, vieillard, waldegard, wasteyard, wild-card, wireguard

10 letters:
afterguard, avantgarde, beauregard, bellegarde, blackguard, body-guard, brouillard, camelopard, campagnard, chainguard, churchyard, co-starred, coastguard, creditcard, crossguard, crowbarred, ddos-guard, drakengard, drouillard, false-card, hildegarde, lettercard, lumberyard, mastercard, montagnard, mouthguard, passegarde, rear-guard, sauvegarde, schoolyard, scotchgard, stableyard, switchyard, timberyard, travelcard, waste-yard, watchguard, yellowcard

11 letters:
avant-garde, avant-guard, banlieusard, barclaycard, cattleguard, charliecard, coast-guard, credit-card, crossbarred, expresscard, ill-starred, molly-guard, paysafecard, scratchcard, self-regard, sneezeguard, splashguard, stack-guard, westergaard, yellow-card

12 letters:
castle-guard, close-barred, colichemarde, counterguard, daughtercard, leather-hard, mailing-card, splash-guard, undersparred

13 letters:
advance-guard

14 letters:
battle-scarred, multimediacard

15 letters:
no-holds-barred

16 letters:
picture-postcard

4 letters:
nerd, curd, herd, word, bird, lord, gird, ford, byrd, ward, cord, hurd

5 letters:
laird, beard, sward, weird, cared, dared, chord, fjord, lured, third, eared, mired, gourd, sherd, horde, hoard, sword, board, wired, award, aired, bored, cured, heard, bared, baird, fared, njord

6 letters:
adored, toward, burred, furred, absurd, afford, geared, reward, inured, aboard, stared, begird, scored, spared, stored, haired, paired, shared, scared, reword, gourde, feared, accord, record, afeard, flared, poured, roared, soared, toured

7 letters:
unheard, matured, revered, blurred, expired, ignored, slurred, attired, stirred, endured, floored, sheared, afeared, assured, spurred, smeared, secured, cleared, squared, retired, chaired, insured, cheered, there'd, unaired, uncured, where'd

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

9 letters:
reassured, preferred, uninsured, unsecured, conferred, prerecord, overheard, uncolored, besmeared, disaccord, dog-eared, longbeard, one-third, pioneered, unattired, uncleared, undergird, unsheared

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

11 letters:
disappeared, volunteered, transferred, back-geared, quick-eared, sharp-eared, smoke-cured, underscored

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

13 letters:
double-geared

16 letters:
hearing-impaired