bastard

a child born to parents who are not married to each other, especially when this is considered socially unacceptable

hijo ilegítimo, bastardo

Collocations bastard child

• He was a bastard by birth.

  Era un bastardo por nacimiento.

an insulting word used to show that you are angry with or criticizing someone, especially a man

maldito, hijo de puta (vulgar)

Collocations call sb a bastard

• He called his boss a bastard.

  Lo llamó un maldito.