verb, nod⋅ded, nod⋅ding, noun | 1. | to make a slight, quick downward bending forward of the head, as in assent, greeting, or command. |
| 2. | to let the head fall slightly forward with a sudden, involuntary movement when sleepy. |
| 3. | to doze, esp. in a sitting position: The speaker was so boring that half the audience was nodding. |
| 4. | to become careless, inattentive, or listless; make an error or mistake through lack of attention. |
| 5. | (of trees, flowers, plumes, etc.) to droop, bend, or incline with a swaying motion. |
| 6. | to bend (the head) in a short, quick downward movement, as of assent or greeting. |
| 7. | to express or signify by such a movement of the head: to nod approval; to nod agreement. |
| 8. | to summon, bring, or send by a nod of the head. |
| 9. | to cause (something) to lean or sway; incline. |
| 10. | a short, quick downward bending forward of the head, as in assent, greeting, or command or because of drowsiness. |
| 11. | a brief period of sleep; nap. |
| 12. | a bending or swaying movement. |
| 13. | nod off, to fall asleep or doze, esp. in a sitting position: He was reprimanded for nodding off in class. |
| 14. | nod out, Slang. to fall asleep, esp. owing to the effects of a drug. |
| 15. | give the nod to, Informal. to express approval of; agree to: The board gave the nod to the new proposal. |
| 16. | on the nod,
|

nod off
Fall asleep momentarily, doze, as in Grandma spends a lot of time in her rocking chair, nodding off now and then. This expression alludes to the quick involuntary dropping of one's head from an upright position when drowsy or napping. The verb nod alone was so used from the mid-1500s. Also see drop off, def. 1.