Definition from Wiktionary, the free dictionary
Hail Mary (plural Hail Marys)
- (Roman Catholicism) A prayer calling for the intercession of the Holy Mother, for Catholics an essential element of the rosary, and with use in certain other denominations.
- (American football) A long forward pass with little chance of completion, typically used when time is running out and no other play is practical.
- (by extension) An act done in desperation, with only a very small chance of success.