Or search: rod, pole, pose, yard, roost, alight, percoidean, percomorphi
2 Syllables: SU
burnings, burnished, churches, churlish, courage, curses, Curtis, earnest, earnings, Ernest, flourish, furnish, furtive, girlish, merges, nourish, nurses, Perkins, purges, purplish, purses, scourges, searches, service, skirmish, surfaced, surges, Turkish, turnings, urges, verses, worketh, workings, yearnings
3 Syllables: SUU
emerges
3 Syllables: USU
assertive, coercive, discourage, discursive, encourage, researches, reverses, subversive

Found 43 words across 3 groupings. Skipped 6 excess words of a similar stem.