(old).1. A symbol of cuckoldry, the letter being occasionally printed in that connection. Hence TO MAKE V = to make HORNS (q.v.): the first and second fingers are derisively forked out: cf. CUNNY-THUMB.
1611. CHAPMAN, May-Day, iv. As often as he turns his back to me, I shall be here V with him.
2. (American).A five-dollar note: V is marked prominently to indicate its value.