Or search: keen, acute, incisive, piercing, knifelike, perceptive, discriminating
4 Syllables: SUUU
celebrating, decorating, deprecating, desolating, devastating, educating, elevating, emanating, emigrating, estimating, generating, hesitating, meditating, separating
5 Syllables: USUUU
accelerating, commemorating, degenerating, disseminating, investigating, perpetuating, regenerating

Found 21 words across 2 groupings.