Or search: cheerily, pleasantly
3 Syllables: SUU
clumsily, custody, cutlery, drudgery, functionally, gluttony, luckily, lustily, nationally, nunnery, rationally, shrubbery, subtly, summary, Tuscany
3 Syllables: USU
discovery, recovery
4 Syllables: USUU
conditionally, exceptionally, microscopy, originally, proportionally, provisionally, traditionally, unluckily
5 Syllables: UUSUU
educationally, unconditionally, unintentionally
6 Syllables: UUUSUU
involuntarily

Found 29 words across 5 groupings.