Here's what rhymes with substansive.
expansive Words that almost rhyme with substansive
stances lances manses prances finances glances expanses enhances romances allegiances refinances passive massive adaptive captive impassive attractive reactive inactive proactive hyperactive overactive interactive refractive unattractive maladaptive combative extractive vasoactive psychoactive nonactive radioactive contrastive retroactive counteractive putrefactive nonreactive nonradioactive immunoreactive