2 Syllables: SU
barrel, Bethel, Carol, Carroll, devil, dreadful, Eccles, Ethel, ethyl, Federal, festal, fretful, gentle, Gerald, Harold, Hegel, Herald, kennel, kettle, level, levelled, levels, medal, meddle, Merrill, metal, methyl, mettle, nestle, nettle, pebble, pedal, peril, pestle, petal, phenol, rebel, revel, revelled, revels, Reynolds, settle, special, speckled, spectral, sterile, treble, vessel, vestal, wrestle
3 Syllables: USU
ancestral, dishevelled, especial, Ezekiel, Fitzgerald, forgetful, imperil, imperilled, neglectful, orchestral, projectile, respectful, unsettled
4 Syllables: UUSU
accidental, continental, departmental, detrimental, disrespectful, elemental, fundamental, instrumental, monumental, Oriental, sentimental, transcendental
5 Syllables: UUUSU
6 Syllables: UUUUSU
Found 78 words across 5 groupings. Skipped 23 excess words of a similar stem.