Read the dictionary definition of nod. All definitions for this word.
1. the act of nodding the head
2. a sign of assent or salutation or command
3. be almost asleep
1. The old man sat nodding by the fireplace
4. let the head fall forward through drowsiness
1. The old man was nodding in his chair
5. lower and raise the head, as to indicate assent or agreement or confirmation
1. The teacher nodded when the student gave the right answer
6. express or signify by nodding
1. He nodded his approval
7. sway gently back and forth, as in a nodding motion
1. the flowers were nodding in the breeze