Or search: aide, helper, adjunct, adjuvant, accessory, ancillary, supporter, subsidiary, supportive, supplemental, supplementary
3 Syllables: SUU
brilliancy, brilliantly, Hilary, pillory, silvery, skilfully, skillfully, tertiary, wilfully
4 Syllables: SUUU
breviary
4 Syllables: USUU
artillery, auxiliaries, familiarly
5 Syllables: USUUU
incendiary, judiciary, pecuniary, subsidiary
6 Syllables: UUSUUU
beneficiary, intermediary
7 Syllables: UUUSUUU
plenipotentiary

Found 20 words across 6 groupings.