3 syllables:
thetically

4 syllables:
aesthetically, aphetically, ascetically, athletically, auxetically, balletically, bathetically, cosmetically, eidetically, emetically, esthetically, frenetically, gametically, genetically, kinetically, luetically, mimetically, phonetically, phrenetically, phyletically, poetically, prophetically, prosthetically, prothetically, syndetically, synthetically

5 syllables:
heretically, hermetically, magnetically, paretically, pathetically, alphabetically, anesthetically, antithetically, apathetically, arithmetically, asyndetically, catechetically, cybernetically, dietetically, diuretically, empathetically, energetically, exegetically, geodetically, homiletically, hypothetically, inergetically, kinaesthetically, kinesthetically, metathetically, quodlibetically

6 syllables:
parenthetically, sympathetically, antipathetically, apologetically, autogenetically, biogenetically, biosynthetically, chemosynthetically, cladogenetically, cytogenetically, diagenetically, diamagnetically, epexegetically, epigenetically, geomagnetically, logarithmetically, morphogenetically, ontogenetically, orthogenetically, palingenetically, paramagnetically, peripatetically, photosynthetically, phylogenetically, polyphyletically, telekinetically, unenergetically, unsympathetically

7 syllables:
cataphoretically, abiogenetically, electromagnetically, parasympathetically, parthenogenetically, psychotomimetically, unapologetically

8 syllables:
electrophoretically, onomatopoetically

3 syllables:
devisee, registry, entity, jestingly, levity, ethnically, dentistry, density, emily, enmity, medically, lenity, effigy, helsinki, pleadingly, negligee, deviltry, legibly, self-pity, chemistry, selfishly, astheny, el misti, evenki, hellishly, pettishly, prelacy, sceptically, temptingly, threateningly, yenisey

4 syllables:
integrity, elegantly, residency, equitably, technically, expensively, domestically, extensively, successively, ethically, coquettishly, yosemite, devilishly, selectively, aggressively, affectingly, refreshingly, indemnity, hygienically, penitently, objectively, professedly, identity, effectively, expressively, necessity, attentively, delicacy, celebrity, hesitancy, offensively, complexity, collectedly, respectively, dementedly, hesitantly, distressingly, immensity, protectively, authentically, impressively, plentifully, dejectedly, obscenity, subjectively, defensively, intensity, propensity, excessively, progressively, collectively, deceptively, symmetrically, hectically, skeptically, obsessively, suggestively, unendingly, unethically, unselfishly

5 syllables:
infidelity, asymmetrically, overwhelmingly, comprehensively, apprehensively, unexpectedly, imperceptibly, intelligently, academically, geometrically, condescendingly, ineffectively, indelicacy, effeminacy, inelegantly, act reflexively, anti-semite, inattentively, inexpensively, inexpressively, inoffensively, move reflexively, reprehensively, unimpressively, unrelentingly, unsymmetrically

6 syllables:
unintelligibly, argumentatively, unintelligently, die unexpectedly, noncomprehensively

7 syllables:
radiotelegraphy

8 syllables:
urinary hesitancy