Or search: lenitive, moderating, mitigatory, mitigative, alleviative
4 Syllables: SUUU
dilatory, dormitory, laboratory, laudatory, mandatory, migratory, oratory, predatory, prefatory, preparatory, purgatory, statutory, transitory
5 Syllables: SUUUU
circulatory, dedicatory, regulatory, respiratory
5 Syllables: USUUU
compensatory, conciliatory, confirmatory, conservatory, consolatory, contributory, declaratory, depository, derogatory, explanatory, exploratory, inflammatory, inhibitory, obligatory, observatory, prohibitory, reformatory, repository, retaliatory
6 Syllables: USUUUU
anticipatory, congratulatory, discriminatory

Found 39 words across 4 groupings.