irrevocable (adj) - irreversible or unalterable; unable to be called back [ih-rev-uh-kuh-buhl]
BREAKDOWN: IR- (not) + RE- (back) + VOC- (call) + -ABLE (able to be)
revoke means to cancel, or call back
See also: unequivocal, supervocalic
“I think that children have a power to imagine that is almost magical when compared to the adult imagination, and this is something irrevocable that a child loses when he or she becomes bound by logic.”— Joseph Weizenbaum