Definition from Wiktionary, the free dictionary
The origin of this expression is uncertain, but it is likely that it arose in the American southwest during the late 1800s. The Cambridge Dictionary makes an unattributed claim that the term is of Australian origin.
- (idiomatic, slang) A stalemate, or a confrontation between two or more sides that no side can win.
- (idiomatic, slang specifically) A confrontation between two or more armed parties, neither of which wants to attack first (fearing that the other could retaliate), but neither of which will disarm (for fear the other will attack).
- (rail transport) A near-collision between two trains, an averted cornfield meet.
- Mexican standoff, in the Cambridge Dictionary published by Cambridge University Press (2009-12-19)