'Accuser' in the Bible

Appoint over him a wicked [man], and let an accuser stand at his right [hand].

{Settle the case quickly with your accuser} while you are with him on the way, lest your accuser hand you over to the judge, and the judge to the officer, and you be thrown into prison.

For as you are going with your accuser before the magistrate, make an effort to come to a settlement with him on the way, so that he will not drag you to the judge, and the judge will hand you over to the bailiff, and the bailiff will throw you into prison.

And I heard a loud voice in heaven saying, "Now the salvation and the power and the kingdom of our God and the authority of his Christ have come, because the accuser of our brothers has been thrown down, the one who accuses them before our God day and night.