glass jawn.► Sports. Vulnerability of a boxer to a knockout punch.
► Vulnerability, especially of a public figure, to destructive criticism.
[TahlilGaran] American Dictionary ▲
glass jaw n.,
slang The inability of a boxer to get a hard punch on the jaw without being knocked out; a tendency to be knocked out easily.
He would have been champion except for his glass jaw. [TahlilGaran] English Idioms Dictionary ▲