to plead guilty or confess in return for receiving a lighter sentence.
to plead guilty to a lesser charge as a means of bargaining one's way out of standing trial for a more serious charge; plea-bargain.
He never copped out on a friend in need. You agreed to go, and you can't cop out now.
to avoid one's responsibility, the fulfillment of a promise, etc.; renege; back out (often fol. by on or of&hasp;):He never copped out on a friend in need. You agreed to go, and you can't cop out now.