A familiar or rough second-person pronoun meaning “you.” Often used informally and can sound rude depending on context.
あんた、今何をしているの？
You—what are you doing right now?
あんたのせいでパーティーが台無しになったよ。
Because of you, the party was ruined.
そんなことを言うのは、あんたくらいだよ。
You're one of the few people who would say something like that.