Or search: antihistamine
2 Syllables: SU
Billy, Chile, Chili, chilly, filthy, guilty, hilly, lilies, Lilly, lily, milky, pristine, really, silky, silly, Willie, willy
3 Syllables: USU
Achilles, tranquilly
4 Syllables: UUSU
unresisting

Found 20 words across 3 groupings.