2 Syllables: SU
breakfast, deadliest, dexterous, exits, extras, headless, lettuce, necklace, plexus, readiest, reckless, redness, sexes, texas, wreckage
3 Syllables: USU
4 Syllables: UUSU
Found 19 words across 3 groupings. Skipped 1 excess word of a similar stem.