NOD

Definition

1. noun a sign of assent or salutation or command.
2. noun the act of nodding the head.
3. verb express or signify by nodding.
4. verb lower and raise the head, as to indicate assent or agreement or confirmation.
5. verb let the head fall forward through drowsiness.
6. verb sway gently back and forth, as in a nodding motion.
7. verb be almost asleep.