glass jaw

1. An excessive vulnerability to being injured or rendered unconscious by blows to the jaw, face, or head. Said especially of boxers. The loudmouth boxing champion claimed his upcoming opponent had a glass jaw that he was looking forward to shattering. Jason is so muscular and tough looking that I was really surprised by his glass jaw. I mean, a dude 30 pounds lighter than him laid him out with one punch! I know Will dreams of being a boxer, but with his glass jaw? He won't make it far.

2. A boxer who is easily knocked out by blows to the jaw, face, or head. A: "Do you think Morrison has a chance at taking the title?" B: "Nah, the guy is a glass jaw. He'll go down by the fifth round, I bet." Once you get a reputation as a glass jaw, every drunk in a bar thinks they can knock you out. It's pretty irritating. Please, my grandmother could win a fight against that glass jaw! You'll be fine.

3. An inability to withstand or tolerate criticism or personal attacks. The political candidate talks tough, but he had a real glass jaw as soon as he was called out on his hypocrisy during the debate. For your own sake, do not criticize Aaron's novel. He has such a glass jaw when it comes to his writing. You can't have a glass jaw if you're going to be in the public eye. You just have to accept that people are gonna judge you.