1. An insult/comeback that can humiliate the most big-headed dumb asses.
2. An action or statement that utterly embarrasses the doer or sayer.
1. Prometheus: You are to me as a swarm of ants to a pubic mound!
Bob: Touche! That was ego-bending...
2. In biology: "Masticate?! Are you serious?! HAHAHA!"