Or search: cuss, pest, blighter
2 Syllables: SU
settler
3 Syllables: SUU
creditor, deserter, editor, Eleanor, Hereford, mariner, registers, Senator, treasurer, Westerners
4 Syllables: USUU
competitor, developer, inheritor, investiture

Found 15 words across 3 groupings. Skipped 8 excess words of a similar stem.