Mexican Standoff Definition

noun

A general stalemate, often with the threat of violent confrontation.

Webster's New World

(idiomatic, slang) A stalemate, or a confrontation between two or more sides that no side can win.

Wiktionary

(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).

Wiktionary

(rail transport) A near-collision between two trains, an averted cornfield meet.

Wiktionary

Origin of Mexican Standoff

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.

From Wiktionary