3 syllables:
ministry, gimmickry, frigidly, trippingly, civilly, mimicry, wickedly, rigidly, whimsically, swimmingly, killingly, wittingly, resignedly, limpidly, typically, impishly, filthily, realty, trinity, willingly, imagery, hillbilly, principally, fittingly

4 syllables:
vindictively, exquisitely, sanguinity, incisively, sublimity, judiciously, specifically, cupidity, unwittingly, physically, acclivity, validity, terrifically, declivity, lucidity, spheniscidae, indistinctly, critically, stupidity, vicinity, virginity, submissively, excitingly, frigidity, putridity, simplicity, befittingly, admittedly, iniquity, unwillingly, duplicity, cynically, derisively, affinity, lividity, plasticity, obliquity, malignity, publicity, capriciously, benignity, acridity, complicity, ubiquity, motivity, stolidity, convincingly, ethnicity, passivity, infinity, liquidity, linguistically, gravidity, activity

5 syllables:
unconvincingly, unanimity, positivity, politically, expansivity, sensitivity, refractivity, transitivity, inactivity, serendipity, resistivity, intrinsically, productivity, receptivity, objectivity, anonymity, absorptivity, equanimity, uncritically, multiplicity, longanimity, synchronicity, directivity, authenticity, perceptivity, reflexivity, statistically, indecisively, realistically, concentricity, subjectivity, impassivity, alternatively, conservatively, informatively

6 syllables:
characteristically, hyperactivity, unrealistically, intransitivity, optimistically, scientifically, uninformatively

7 syllables:
photosensitivity

8 syllables:
radiosensitivity