Or search: deem, moot, mull, muse, dally, favor, liken, weigh, prise, groak, reify, debate, equate, esteem, favour
2 Syllables: SU
bristling, christening, crippling, differing, giggling, glistening, listening, middling, nibbling, rippling, scribbling, sickening, stiffening, thickening
3 Syllables: SUU
bickering, blistering, dissident, figuring, flickering, glimmering, glittering, glycerine, limiting, Pickering, picturing, quickening, quivering, rivalling, shimmering, shivering, simmering, synonym, tickling, whispering, withering, wriggling
4 Syllables: USUU
conditioning, delivering, eliciting, imprisoning, inhibiting, petitioning, positioning, prohibiting, soliciting

Found 45 words across 3 groupings. Skipped 2 excess words of a similar stem.