bas ‧ tard /ˈbɑːstəd, ˈbæ- $ ˈbæstərd/ BrE AmE noun [countable]
[ Date: 1300-1400 ; Language: Old French ; Origin: Medieval Latin bastardus , probably from bastum 'saddle for carrying bags' ; probably from the idea of a child produced as a result of sex with a traveler ]
1 . taboo a very offensive word for someone, especially a man, who you think is unpleasant. Do not use this word.:
You lying bastard!
2 . spoken informal not polite a man who you think is very lucky or very unlucky – often used humorously:
He’s gone straight to the top, the lucky bastard.
The poor bastard fell off his horse.
3 . British English spoken informal something that causes difficulties or problems:
Life’s a bastard sometimes.
4 . old-fashioned someone who was born to parents who were not married