noun
- The definition of a nod is an up and down movement of the head, usually to show agreement or tiredness.
An example of a nod is a dropping forth of the head when almost falling asleep in class.
- Nod is defined as to quickly raise and lower the head, usually for showing agreement or tiredness.
An example of to nod is to agree with someone by a movement of the head.
nod

intransitive verb
nod′ded, nod′ding- to bend the head forward slightly and raise it again quickly, as a sign of greeting, command, acknowledgment, invitation, or, specif., of agreement or assent
- to let the head fall forward involuntarily because of drowsiness; be very sleepy
- to be inattentive or careless; make a slip
- to sway back and forth or up and down, or to hang down, as the tops of trees
- Slang to be under the influence of a drug, as heroin
Origin of nod
Middle English nodden, probably in basic sense “to shake the head,” akin to German notten, to move about, Old High German hnot?n, to shake, Old English hnossian, to knock from Indo-European an unverified form kneudh from base an unverified form ken-, to scratch, scrape from source nip- to bend (the head) forward slightly and raise it again quickly
- to signify (assent, approval, agreement, etc.) by doing this
- to invite or dismiss by a nod
- a nodding, as of the head, treetops, etc.
- a sign of affirmation, assent, favorable decision, etc.: to give or get the nod
nod Idioms
nod off
to fall asleep, esp. when sitting up
nod out
Slang to become unconscious from the effects of a drug
nod

verb
nod·ded, nod·ding, nodsverb
intransitive- To lower and raise the head quickly, as in agreement or acknowledgment.
- To let the head fall forward when sleepy.
- To be careless or momentarily inattentive as if sleepy; lapse: Even Homer nods.
- To sway, move up and down, or droop, as flowers in the wind.
verb
transitive- To lower and raise (the head) quickly in agreement or acknowledgment.
- To express by lowering and raising the head: nod one's agreement.
- To summon, guide, or send by nodding the head: She nodded us into the room.
noun
- A forward or up-and-down movement of the head, usually expressive of drowsiness or agreement: a nod of affirmation.
- An indication of approval or assent: The contestant got the nod from the judges.
- Informal A nomination for an award.
Origin of nod
Middle English nodden perhaps akin to Middle High German nottenRelated Forms:
- nod′der
noun
nod

Initialism
- (law) Notice Of Disagreement; filed by an appellant in response to a denial of veteran's benefits in United States law.