3 syllables:
-ectomy, ectomy

4 syllables:
antrectomy, arthrectomy, bullectomy, bursectomy, canthectomy, carpectomy, cecectomy, cheilectomy, cirsectomy, colectomy, colpectomy, cordectomy, corectomy, corpectomy, costectomy, cystectomy, discectomy, diskectomy, frenectomy, fundectomy, gastrectomy, glomectomy, glossectomy, gyrectomy, isthmectomy, lensectomy, lipectomy, lobectomy, lumpectomy, mammectomy, mastectomy, myectomy, necrectomy, nephrectomy, neurectomy, nymphectomy, orchectomy, ostectomy, penectomy, phallectomy, phlebectomy, phrenectomy, pleurectomy, pneumectomy, proctectomy, radectomy, rectectomy, sclerectomy, septectomy, splenectomy, strumectomy, syndesmectomy, tarsectomy, tenectomy, testectomy, thrombectomy, thymectomy, topectomy, tubectomy, tylectomy, typhlectomy, vasectomy, vaxectomy, vitrectomy, vulvectomy

5 syllables:
adenectomy, adipectomy, adnexectomy, apicectomy, appendectomy, atherectomy, blepharectomy, bunionectomy, callosectomy, capsulectomy, cardiectomy, cervicectomy, clitorectomy, coccygectomy, craniectomy, embolectomy, embryectomy, enterectomy, ethmoidectomy, facetectomy, fasciectomy, fistulectomy, fundusectomy, gangliectomy, gingivectomy, gonadectomy, hepatectomy, hymenectomy, hysterectomies, hysterectomy, iridectomy, jejunectomy, keratectomy, laminectomy, laparectomy, laryngectomee, laryngectomy, lymphangiectomy, mastoidectomy, meniscectomy, mucosectomy, myomectomy, myringectomy, necrosectomy, odontectomy, omentectomy, omphalectomy, onychectomy, oophorectomy, ophthalmectomy, orchidectomy, orchiectomy, patellectomy, peritectomy, pharyngectomy, pneumonectomy, polypectomy, prostatectomy, pylorectomy, quadrantectomy, rhytidectomy, salpingectomy, segmentectomy, sequestrectomy, sigmoidectomy, stapedectomy, sympathectomy, synovectomy, tenonectomy, thyroidectomy, tonsillectomy, trachelectomy, turbinectomy, tympanectomy, urethrectomy, uvulectomy, vaginectomy, vertebrectomy

6 syllables:
adenoidectomy, adrenalectomy, alveolectomy, aneurysmectomy, apicoectomy, appendicectomy, arteriectomy, astragalectomy, cholecystectomy, clitoridectomy, duodenectomy, endarterectomy, esophagectomy, haemorrhoidectomy, hemicolectomy, hemiglossectomy, hemipelvectomy, hemispherectomy, hemorrhoidectomy, hydrocelectomy, hypophysectomy, labyrinthectomy, lymphadenectomy, nephroureterectomy, oesophagectomy, ovariectomy, pancreatectomy, panhysterectomy, panniculectomy, parotidectomy, pericardectomy, pinealectomy, proctocolectomy, radiculectomy, simple mastectomy, sympathetectomy, trabeculectomy, ureterectomy, vermilionectomy

7 syllables:
acetabulectomy, angioneurectomy, chemopallidectomy, costotransversectomy, cryothalamectomy, cystoprostatectomy, dacryocystectomy, diverticulectomy, epididymectomy, gastropylorectomy, hemicorporectomy, hemicraniectomy, hemilaminectomy, hemithyroidectomy, oophorocystectomy, parathyroidectomy, pericardiectomy, proctosigmoidectomy, radical mastectomy, suprarenalectomy, thromboembolectomy, thromboendarterectomy, total hysterectomy, varicocelectomy

8 syllables:
adenotonsillectomy, hysteromyomectomy, hysterosalpingectomy, laparohysterectomy, oophorosalpingectomy, radical hysterectomy, ureteronephrectomy

9 syllables:
abdominohysterectomy, hystero-oophorectomy, ovariohysterectomy, salpingo-oophorectomy

10 syllables:
modified radical mastectomy, pancreatoduodenectomy

11 syllables:
pancreaticoduodenectomy

12 syllables:
hysterosalpingo-oophorectomy

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

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

5 syllables:
accidentally, acrocephaly, anencephaly, biochemistry, change integrity, change intensity, clinocephaly, coalescency, conscientiously, consequentially, create mentally, deferentially, detrimentally, disrespectfully, drunken revelry, field intensity, fundamentally, geochemistry, half-intensity, high-fidelity, high fidelity, hydrocephaly, incidentally, independency, independently, intumescency, life expectancy, line of destiny, macrocephaly, mask of pregnancy, megacephaly, microcephaly, mortal enemy, mountain ebony, nanocephaly, naval weaponry, of necessity, open sesame, penitentially, photochemistry, providentially, reprehensibly, reverentially, scaphocephaly, school of dentistry, sentimentally, tubal pregnancy, unacceptably, unforgettably, unintentionally, unpretentiously, unrepentantly, unsuccessfully, vapor density, white supremacy

6 syllables:
anas penelope, change of integrity, coincidentally, cosmetic dentistry, electrochemistry, environmentally, experimentally, genus penelope, immunochemistry, inconsequentially, interdependency, manifest destiny, militant tendency, organic chemistry, pedal extremity, physical chemistry, radiochemistry, relative density, unsentimentally

7 syllables:
abdominal pregnancy, department of chemistry, executive clemency, feeling of identity, inorganic chemistry, john fitzgerald kennedy, magnetic flux density, magnetic intensity, ovarian pregnancy

8 syllables:
conformational entropy, interpersonal chemistry