3 syllables:
ecipe, praecipe, precipe

2 syllables:
thessaly

3 syllables:
ecstasy, especially, debauchee, specialty, presently, destiny, heavily, heavenly, medically, endlessly, empathy, jealously, chemically, penalty, benghazi, dextrously, ectropy, emigree, evilly, fecklessly, jejunely, legibly, lemony, lenity, melanie, pebbly, pederasty, penally, resiny, self-pity, selflessly, senselessly, sentiency, stephanie, tepidly, trenchancy, trepidly, vengefully, yemeni, zestily, severally, splendidly, pleasantly, messily, tendency, ebony, pedigree, credibly, gemini, venally, leprosy, prelacy, lengthily, elegy, readily, tenantry, weaponry, helplessly, equity, zestfully, remedy, breathlessly, brevity, revelry, flexibly, melody, steadily, entity, jealousy, restfully, enemy, seventy, entropy, tensity, peasantry, clemency, velvety, threnody, sensibly, devilry, chemistry, pedantry, pregnancy, legacy, bestially, cecity, necropsy, sesame, zealotry, mentally, density, dreadfully, helpfully, testily, specially, embassy, tenancy, pleasantry, centrally, kennedy, deputy, secondly, enmity, legatee, felony, preciously

4 syllables:
indemnity, incessancy, separately, telepathy, licentiously, low density, regrettably, thrombectomy, tentatively, infectiously, penelope, acephaly, confessedly, defencelessly, domenici, forelady, illegibly, immensity, impendency, impetuously, inclemency, jack kennedy, lieutenancy, neurectomy, perplexedly, polemically, pretentiously, professedly, quiescency, refreshfully, relentlessly, revengefully, shell entity, unhelpfully, vulvectomy, with empathy, theosophy, incessantly, rebelliously, transcendency, detestably, acceptably, resplendently, extremity, ascendancy, nonentity, mastectomy, expectancy, identity, necessity, dependably, lamentably, successfully, inequity, discrepancy, sequentially, unsteadily, lobectomy, ascendency, preferably, serenity, fidelity, unpleasantly, nephrectomy, potentially, death penalty, tremendously, essentially, flux density, desperately, schenectady, lumpectomy, intrepidly, ostensibly, sententiously, complexity, splenectomy, insensibly, telemetry, respectfully, respectably, hegemony, generally, inflexibly, dependency, supremacy, anemone, longevity, repentantly, ineffably, perplexity, vasectomy, resplendency, solemnity, contemptuously, amenity, federally, intensity, heredity, perceptibly, convexity, incredibly, integrity, allegedly

5 syllables:
microcephaly, fundamentally, vapor density, anencephaly, reprehensibly, unsuccessfully, acrocephaly, change integrity, change intensity, clinocephaly, coalescency, create mentally, detrimentally, drunken revelry, field intensity, half-intensity, high-fidelity, hydrocephaly, intumescency, laminectomy, laryngectomy, line of destiny, macrocephaly, megacephaly, meniscectomy, mortal enemy, mountain ebony, nanocephaly, naval weaponry, of necessity, scaphocephaly, school of dentistry, sigmoidectomy, unforgettably, unpretentiously, unrepentantly, tonsillectomy, orchidectomy, geochemistry, mask of pregnancy, hysterectomy, eventually, sympathectomy, life expectancy, sentimentally, exceptionally, consequentially, confederacy, biochemistry, accidentally, mastoidectomy, independently, tubal pregnancy, reverentially, oophorectomy, white supremacy, professionally, stapedectomy, orchiectomy, pneumonectomy, salpingectomy, thyroidectomy, disrespectfully, appendectomy, penitentially, irreverently, macrencephaly, abstemiously, rhytidectomy, incidentally, intemperately, open sesame, providentially, high fidelity, prostatectomy, unacceptably, deferentially, photochemistry, independency, conscientiously, embolectomy

6 syllables:
cosmetic dentistry, inconsequentially, adrenalectomy, immunochemistry, relative density, adenoidectomy, anas penelope, appendicectomy, change of integrity, genus penelope, militant tendency, ovariectomy, panhysterectomy, pedal extremity, unsentimentally, cholecystectomy, unconventionally, coincidentally, biogeography, unintentionally, environmentally, radiochemistry, physical chemistry, simple mastectomy, impetuosity, manifest destiny, interdependency, electrochemistry, organic chemistry, cercopithecidae, experimentally

7 syllables:
department of chemistry, executive clemency, feeling of identity, john fitzgerald kennedy, magnetic intensity, suprarenalectomy, ovarian pregnancy, radical mastectomy, inorganic chemistry, magnetic flux density, paleogeography, abdominal pregnancy, total hysterectomy

8 syllables:
conformational entropy, interpersonal chemistry, radical hysterectomy

10 syllables:
modified radical mastectomy