define wag
v. wagged, wagÂ·ging, wags. v. intr. 1. To move briskly and repeatedly from side to side, to and fro, or up and down: The dog's tail wagged. 2. To move rapidly in talking. Used of the tongue.3.Archaic To be on one's way; depart.. tr. To move (a body part) rapidly from side to side or up and down, as in playfulness, agreement, or admonition: wagged his finger at the giggling students. n. The act or motion of wagging: a farewell wag of the hand.