Here's what rhymes with relinquishment.

Consider these alternatives

reassertion / person presupposed / most abrogation / education relinquishing / distinguishing renunciation / relation untruthfulness / usefulness reversion / person changeability / stability mispronunciations / relations postulation / education renunciations / relations corrugations / relations requisition / position acquiesce / less relinquishes / distinguishes disavowal / vowel immobilisation / relation unsuitability / stability invalidation / operation permissibility / ability effluvia / minutiae