2 Syllables: SU
Burgess, circuit, circus, courteous, Curtis, earliest, Ernest, fervid, firmest, firmness, furnace, furthest, girded, hermit, kerchief, nervous, Perseus, purchase, purpose, service, spurious, sternest, sternness, stirrup, surface, surfeit, surplus, syrup, target, turnip, turret, versus, worship, worshipped, worthiest, worthless
3 Syllables: USU
alertness, asserted, averted, concerted, illustrious, impervious, industrious, inserted, interpret, luxurious, reasserted
4 Syllables: UUSU
Found 48 words across 3 groupings. Skipped 7 excess words of a similar stem.