What is to incline the head with a quick motion; to make a slight bow; to make a motion of assent, of salutation, or of drowsiness, with the head; as, to nod at one called?

nod — To incline the head with a quick motion; to make a slight bow; to make a motion of assent, of salutation, or of drowsiness, with the head; as, to nod at one. (Webster's 1913.)

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