2 Syllables: SU
barrel, Bethel, Carol, Carroll, devil, dreadful, Eccles, Ethel, ethyl, festal, fretful, general, 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: SUU
bearable, cerebral, clerical, credible, decimal, edible, equable, festival, genital, legible, medical, parable, pedestal, plentiful, preferable, Reginald, seminal, several, skeletal, tenable, terrible
3 Syllables: USU
ancestral, dishevelled, especial, Ezekiel, Fitzgerald, forgetful, imperil, imperilled, neglectful, orchestral, projectile, respectful, unsettled
4 Syllables: USUU
accessible, amenable, chimerical, confessional, congenital, Congressional, conjectural, detestable, electoral, ephemeral, execrable, illegible, impeccable, incredible, ineffable, numerical, polemical, professional, regrettable, unbearable, untenable
4 Syllables: UUSU
accidental, continental, departmental, detrimental, disrespectful, elemental, fundamental, instrumental, monumental, Oriental, sentimental, transcendental
5 Syllables: UUSUU
architectural, hypothetical, inaccessible, incontestable, indigestible, inexpressible, irrepressible, unforgettable
5 Syllables: UUUSU
6 Syllables: UUUSUU
6 Syllables: UUUUSU
Found 129 words across 9 groupings. Skipped 29 excess words of a similar stem.