N-COUNT [usually singular] 老疯子；讨厌的老家伙；（尤指）癫婆子，招嫌的老太婆 If someone refers to an old person, especially an old woman, as an old bat, they think that person is silly, annoying, or unpleasant. 老疯子；讨厌的老家伙；（尤指）癫婆子，招嫌的老太婆 [informal, offensive, disapproval]