Defoliant rhymes with:
salient, affiant, ambient, cordiant, deviant, disobedient, expedient, gradient, incipient, ingredient, invariant, lenient, luxuriant, miscreant, nutrient, obedient, percipient, prescient, prurient, radiant, recipient, salient, subservient, variant
Defoliant sounds like:
deployment, diplomat, divalent