nod

a sign of assent or salutation or command

the act of nodding the head

express or signify by nodding; "He nodded his approval"

lower and raise the head, as to indicate assent or agreement or confirmation; "The teacher nodded when the student gave the right answer"

let the head fall forward through drowsiness; "The old man was nodding in his chair"

sway gently back and forth, as in a nodding motion; "the flowers were nodding in the breeze"

be almost asleep; "The old man sat nodding by the fireplace"