2 Syllables: SU
aerial, ariel, barrel, burials, careful, carol, carroll, gerald, harold, herald, merrill, peril, prayerful, sterile
3 Syllables: USU
biennial, centennial, ezekiel, fitzgerald, imperil, imperilled, malarial, perennial, terrestrial, triennial
4 Syllables: UUSU
Found 25 words across 3 groupings. Skipped 3 excess words of a similar stem.