Incapable of being changed or called back.
He had called me stupid and tried to take back those words, but to me, they were irrevocable.
1. Unalterable; unable to be undone
2. That word on the back of the first Twilight novel that nobody knows how to pronounce, or is really sure of what it means
Guy 1: Dude, Jessica told me her love for me is i-re-VO-cable?
Guy 2: She's been reading Twilight again...get out while you can