offensive or archaic an illegitimate child
informal
an offensive or disagreeable person, often used as a general term of abuse
a person of a specified type
lucky bastard
Poor old bastard
something spurious, irregular, inferior, or of questionable origin
bastardly adj
[Middle English from Old French bastart, bastard, perhaps from fils de bast, literally ‘son of the barn’ or ‘son of the packsaddle’]