(~s)
1.
Bastard is an insulting word which some people use about a person, especially a man, who has behaved very badly. (INFORMAL, VERY RUDE)
N-COUNT disapproval
2.
A ~ is a person whose parents were not married to each other at the time that he or she was born. This use could cause offence. (OLD-FASHIONED)
N-COUNT: oft N n