3 syllables:
thetically

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

5 syllables:
alphabetically, anesthetically, antithetically, apathetically, arithmetically, catechetically, cybernetically, dietetically, diuretically, empathetically, energetically, exegetically, geodetically, homiletically, hypothetically, inergetically, kinaesthetically, kinesthetically, metathetically, parenthetically, quodlibetically, sympathetically, theoretically

6 syllables:
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:
abiogenetically, electromagnetically, parasympathetically, parthenogenetically, psychotomimetically, unapologetically

8 syllables:
onomatopoetically

3 syllables:
medically, astheny, chemistry, density, dentistry, devilishly, effigy, el misti, emily, enmity, entity, ethnically, evenki, hellishly, helsinki, jestingly, levity, negligee, pettishly, prelacy, registry, sceptically, selfishly, skeptically, temptingly, threateningly, yenisey

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

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

6 syllables:
unintelligibly, die unexpectedly, noncomprehensively

7 syllables:
radiotelegraphy