Or search: ore, pore, focus, rivet, steep, absorb, digest, engulf, lessen, modify, plunge, decoct, abridge, capsule, cooking
3 Syllables: SUU
commonplace, compensate, complicate, concentrates, confiscate, congregate, conjugate, consecrate, consummate, contemplate, dominate, nominate
4 Syllables: USUU
denominate, predominate, preponderate

Found 15 words across 2 groupings. Skipped 4 excess words of a similar stem.