Or search: layer, gaddi, buffer, damper, modify, pillow, soften, muffler, padding, hassock, headrest, suspension
2 Syllables: SU
bosom, Brooklyn, Buren, Courant, cushioned, cushions, durance, Durham, urine, woman, woman's, wooden, woodland, woolen, woollen
3 Syllables: USU
assurance, insurance, reassurance

Found 18 words across 2 groupings. Skipped 2 excess words of a similar stem.