2 Syllables: SU
bismuth, bridges, busiest, business, Christmas, dishes, fishes, Griffith, isthmus, kisses, listless, mischief, mistress, riches, richest, richness, ridges, Scythians, stiffness, swiftest, swiftness, switches, vicious, visage, viscous, vistas, witches
3 Syllables: USU
ambitious, auspicious, capricious, Corinthians, delicious, factitious, fictitious, forgiveness, judicious, lascivious, malicious, Narcissus, nutritious, oblivious, officious, pernicious, prestigious, prodigious, propitious, religious, seditious, suspicious
4 Syllables: UUSU
adventitious, avaricious, Dionysius, expeditious, injudicious, irreligious, superstitious, surreptitious, unpropitious, unsuspicious
Found 59 words across 3 groupings. Skipped 1 excess word of a similar stem.