nod
n 1: a sign of assent or salutation or command
2: the act of nodding the head [syn: {nutation}]
v 1: express or signify by nodding; "He nodded his approval"
2: lower and raise the head, so as to indicate assent
3: let the head fall forward through drowsiness; "The old man
was nodding in his chair"
4: sway gently back and forth, as of flowers or tress in the
wind [syn: {sway}]
5: be almost asleep; "The old man sat nodding by the fireplace"