In American football, a “Hail Mary” pertains to a very long forward pass. This kind of pass is only made in moments of desperation as they have a very small chance of success.
A wide receiver catches a hail mary pass during a game
First coined in 1975, when quarterback Roger Staubach of the Dallas Cowboys threw a 50-yard pass with just 24 seconds left – his teammate Drew Pearson caught it and their team won. Staubach told the press he said a Hail Mary prayer before releasing the ball.