Or search: rip, seize, steal, thief, hijack, looter, morgan, raider, thatch, corsair, lafitte, roberts, spoiler, stealer, skyjack
2 Syllables: SU
biased, brightest, climate, diet, direst, driest, finest, highest, hybrid, Isaac, lightest, Pilate, pilot, pirates, private, quiet, riot, slightest, violets, widest, wisest, Wyatt
3 Syllables: USU
disquiet, unbiased, unbiassed
4 Syllables: USUU
psychiatrist
4 Syllables: UUSU
carbohydrate, elegiac

Found 28 words across 4 groupings. Skipped 6 excess words of a similar stem.