Hail Mary pass

Meanings

1. A long forward pass with little chance of completion, typically used by the losing team when time is running out and no other play is practical, in a desperate attempt to score the winning points.
2. An act done in desperation, with only a very small chance of success.

Etymology

From Hail Mary, a prayer for intercession, from Latin Ave Maria, plus pass (“moving the ball from one player to another”). Attested from the 1970s in the context of American football.