Or search: mate, hubby, spouse, partner, benedick, benedict, conserve, retrench, economize, economise
2 Syllables: SU
cousin, Covent, custom, dozen, Dutchman, husbands, judgement, judgment, Justin, Muslim, muslin, oven, Prussian, roughened, ruffian, Russian, Tuscan
3 Syllables: USU
accustom, adjustment, Augustan, combustion, concussion, discussion, escutcheon, Etruscan, percussion, readjustment
4 Syllables: UUSU
repercussions, unaccustomed

Found 29 words across 3 groupings. Skipped 15 excess words of a similar stem.