Or search: uncaused, unintended
2 Syllables: SU
causes, cautious, clauses, lodges, loftiest, losses, mosses, nauseous, notches, novice, obvious, office, pauses, sauces, sausage, softest, softness, watches
3 Syllables: USU
colossus, incautious, postoffice, preposterous

Found 22 words across 2 groupings.