2 Syllables: SU
brittle, cereal, cripple, fickle, fiddle, filial, fitful, giggle, lineal, little, middle, nibble, Nichols, nickel, nipple, pickle, quibble, riddle, ripple, scribbled, serial, Sibyl, sickle, signal, signalled, signals, tickle, tittle, trickle, triple, trivial, vitriol, Whipple
3 Syllables: USU
acquittal, arterial, bacterial, belittle, committal, convivial, ethereal, imperial, material, venereal
4 Syllables: UUSU
Found 45 words across 3 groupings. Skipped 15 excess words of a similar stem.