2 Syllables: SU
bilious, bismuth, bridges, busiest, business, Christmas, dishes, fishes, Griffith, hideous, idiots, isthmus, kisses, listless, mischief, mistress, piteous, prettiest, riches, richest, richness, ridges, serious, stiffness, swiftest, swiftness, switches, vicious, visage, viscous, vistas, vitreous, witches
3 Syllables: SUU
3 Syllables: USU
ambitious, amphibious, auspicious, capricious, delicious, delirious, factitious, fastidious, fictitious, forgiveness, imperious, initiates, insidious, invidious, judicious, lascivious, malicious, Mauritius, mysterious, Narcissus, nutritious, oblivious, officious, perfidious, pernicious, prestigious, prodigious, propitious, punctilious, religious, seditious, suspicious
4 Syllables: UUSU
adventitious, avaricious, deleterious, Dionysius, expeditious, ignominious, injudicious, irreligious, supercilious, superstitious, surreptitious, unpropitious, unsuspicious
Found 82 words across 4 groupings. Skipped 1 excess word of a similar stem.