2 Syllables: SU
bilious, busiest, hideous, idiots, illness, piteous, prettiest, serious, stillness, village, villas, vitreous
3 Syllables: SUU
dizziness, giddiness, pitiless, weariness
3 Syllables: USU
amphibious, bacillus, delirious, fastidious, imperious, initiates, insidious, invidious, lascivious, Mauritius, mysterious, oblivious, perfidious, punctilious, utilise
4 Syllables: UUSU
deleterious, Dionysius, ignominious, supercilious

Found 35 words across 4 groupings.