3 syllables:
happily, fractiously, gallantly, thankfully, tapestry, axletree, phantasy, cabinetry, capably, scammony, apogee, chastity, nastily, blasphemy, anthony, sanity, craftily, cavity, banditry, tragedy, balcony, rampantly, gascony, balmily, gravelly, captaincy, galaxy, travesty, fallacy, gravity, patchouli, nascency, stagnancy, damnably, rapidly, cadency, laxity, bashfully, halfpenny, apathy, satiny, faculty, calumny, valiantly, valency, ataxy, abbacy, absently, antony, lazily, baptistery, atrophy, amnesty, majesty, callously, mangabey, maggoty, scantily, practically, anxiously, anomie, angrily, flashily, gallantry, agony, rhapsody, falconry, sassaby, agilely, scrappily, tangency, bankruptcy, passably, saxony, patently, tammany, malady, gadgetry, fantasy, valiancy, family, pageantry, handily, tastily, basketry, cannily, manfully, tactfully, alchemy, plangency, randomly, canopy, affably, manatee, cavalry, vanity, rackety, strategy, rascally

4 syllables:
casually, unhappily, concavity, depravity, rationally, fugacity, casualty, actually, opacity, diastole, alacrity, sagacity, compatibly, catastrophe, audacity, anatomy, substantially, naturally, vivacity, mammalogy, calamity, edacity, pugnacity, insanity, philately, analogy, elaborately, disassembly, academy, type family, profanity, nationally, juglandaceae, rapacity, reality, anastrophe, capacity, philanthropy, pulp cavity, examinee, salacity, voracity, financially, chivalrously, criminally, difficulty, immanency, imminency, impotency, impotently, infinitely, intimacy, intimately, intricacy, intricately, militancy, minimally, misanthropy, mischievously, misogamy, vigilantly, whitsun monday

5 syllables:
perspicacity, understandably, actuality, royal family, circumstantially, incapacity, alismatidae, pertinacity, satisfactorily, gross anatomy, inhumanity, hylobatidae, nasal cavity, irrationally, underhandedly, sensuality, spiral galaxy, oral cavity, unnaturally, acidimetry, additionally, ambivalency, articulately, coincidently, conditionally, elizabeth ii, equivocally, felicitously, grandiloquently, inimitably, legitimacy, legitimately, magnificently, magniloquently, munificently, originally, reciprocally, ridiculously, traditionally, unchivalrously, volitionally

6 syllables:
center of gravity, total depravity, araliaceae, tympanic cavity, pathetic fallacy, specific gravity, unilaterally, amaranthaceae, nuclear family, centre of gravity, ambystomatidae, thoracic cavity, channel capacity, extended family, milky way galaxy, internationally, illegitimacy, illegitimately, inarticulately, indiscriminately, infelicitously, unconditionally, unequivocally

7 syllables:
segmentation cavity, homosexuality, amniotic cavity, abdominal cavity

8 syllables:
microscopic anatomy, military academy