2 Syllables: SU
blushing, brushing, bubbling, bustling, buzzing, clutching, covering, crushing, doubling, dusting, flushing, grudging, gushing, hovering, judging, juggling, Justin, loving, Muslim, nothing, puffing, rushing, Ruskin, rusting, rustling, shoving, shuffling, smuggling, struggling, stuffing, suffering, thrusting, touching, troubling, trudging, trusting
3 Syllables: SUU
blustering, clustering, coloring, coverings, fluttering, mustering, muttering, shuddering, smothering, summoning, uttering
3 Syllables: USU
4 Syllables: USUU
Found 55 words across 4 groupings. Skipped 3 excess words of a similar stem.