Or search: tragedy, calamity, disaster, cataclysm, revelation, catastrophe
3 Syllables: SUU
botanist, choleric, colonist, Dominic, dramatist, obelisk, opposite, politic
4 Syllables: USUU
apologist, biologist, economist, geologists, immoderate
5 Syllables: UUSUU
anthropologist, archaeologist, physiologist, sociologist

Found 17 words across 3 groupings. Skipped 12 excess words of a similar stem.