N-COUNT
If someone refers to an old person, especially an old woman, as an old bat, they think that person is silly, annoying, or unpleasant. 讨厌的老家伙
[非正式，侮辱][usu sing]
Andrews, who worked for the Duchess of York for nine years until 1997, beat 39-year-old Mr Cressman with a cricket bat and stabbed him with a kitchen knife on 17 September 2000.