Or search: fastening, attachment
2 Syllables: SU
bowing, Browning, browsing, crouching, crowding, crowning, Dauphin, doubting, Downing, drowning, fowling, frowning, housing, howling, mowing, outing, ploughing, plowing, prowling, rousing, routing, scouting, scowling, shouting, spouting, sprouting, towering, vowing
3 Syllables: SUU
cowering, flowering, scouring, showering
3 Syllables: USU
accounting, allowing, amounting, arousing, avowing, endowing, espousing
4 Syllables: USUU
devouring, empowering, encountering
4 Syllables: UUSU
overpowering

Found 43 words across 5 groupings.