3 Syllables: SUU
4 Syllables: USUU
captivity, complicity, explicitly, felicity, festivities, festivity, implicitly, invisibly, nativity, proclivities, publicity, simplicity, toxicity
5 Syllables: UUSUU
conductivity, creativity, domesticity, eccentricity, elasticity, electricity, irresistibly, productivity, relativity, selectivity, specificity, unequivocally
Found 31 words across 3 groupings. Skipped 2 excess words of a similar stem.