4 Syllables: SUUU
aggravating, aggregating, agitating, allocating, animating, fascinating, graduating, irrigating, mitigating, propagating, vacillating
5 Syllables: USUUU
collaborating, congratulating, contaminating, elaborating, eradicating, evaporating, exaggerating, exasperating, investigating
Found 20 words across 2 groupings.