5 syllables:
conventionally, dimensionally, extensionally, intensionally, intentionally

6 syllables:
unintentionally

2 syllables:
thessaly

3 syllables:
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, recipe, ecstasy, especially, debauchee, specialty, presently, destiny, heavily, heavenly, medically, endlessly, empathy, jealously, chemically, penalty

4 syllables:
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, indemnity, incessancy, separately, telepathy, licentiously, low density, regrettably, thrombectomy, tentatively, infectiously, penelope, celibacy, cembra nut tree, creditably, credulously, definitely, delicacy, delicately, desolately, eloquently, epigraphy, evidently, gentlemanly, genuinely, petulantly, precedency, presidency, questionably, relevancy, relevantly, reputably, sensually, technocracy, venomously

5 syllables:
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, microcephaly, fundamentally, vapor density, anencephaly, reprehensibly, unsuccessfully, affectionately, antecedency, benevolently, discreditably, disreputably, incredulously, indefinitely, indefinity, ineloquently, inequitably, inevitably, intelligibly, irrelevancy, irrelevantly, malevolency, malevolently, objectionably, obsessionally, pre-eminently, preeminently, ungentlemanly, unquestionably

6 syllables:
cholecystectomy, coincidentally, biogeography, environmentally, radiochemistry, physical chemistry, simple mastectomy, impetuosity, manifest destiny, interdependency, electrochemistry, organic chemistry, cercopithecidae, experimentally, cosmetic dentistry, inconsequentially, adrenalectomy, immunochemistry, relative density, unintelligibly

7 syllables:
ovarian pregnancy, radical mastectomy, inorganic chemistry, magnetic flux density, paleogeography, abdominal pregnancy, total hysterectomy

8 syllables:
radical hysterectomy

10 syllables:
modified radical mastectomy