galvauder

to tarnish, sully, debase, bring into disrepute; to waste; to squander; to overuse, render trite; to be lazy, loaf around; to demean oneself, compromise oneself

“galvauder les dons qu’on a reçus de la nature” — to squander one's natural gifts

Cross between Old French galer (“to enjoy”) and ravauder (“to mend”).