Here's what rhymes with ubstantive.
Words that almost rhyme with ubstantive
punches lunches plunges hunches lunges brunches munches crunches lumpish expunges frumpish scrunches keypunches muskellunges seductive irruptive destructive productive inductive disruptive obstructive ablative disjunctive eruptive vocative reproductive instructive impulsive repulsive conductive subjunctive locative fricative propulsive appositive assumptive mutative combustive lenitive constructive compulsive transitive unproductive presumptive convulsive proliferative consumptive reconstructive nondestructive nonproductive superconductive counterproductive nonconstructive