Hail Mary
noun
(pl. Hail Marys)
1
2
- usu. as modifier US (in American football) a long, typically unsuccessful pass made in an attempt to score late in the game〈美〉（美式橄榄球用语）（比赛将近结束时试图得分但往往失败的）长距离传球。
2.1
- a plan or project with little chance of success无成功希望的计划; 无成功希望的工程项目。