[n] the act of nodding the head
[n] a sign of assent or salutation or command
[v] be almost asleep; "The old man sat nodding by the fireplace"
[v] let the head fall forward through drowsiness; "The old man was nodding in his chair"
[v] lower and raise the head, so as to indicate assent
[v] express or signify by nodding; "He nodded his approval"
[v] sway gently back and forth, as of flowers or tress in the wind