nod >> nɒd
Definition: [verb] lower and raise one's head slightly and briefly, especially in greeting, assent, or understanding, or to give someone a signal.
Example: he looked around for support and everyone nodded
Definition: [verb] let one's head fall forward when drowsy or asleep.
Example: Anna nodded over her book
Definition: [verb] head (the ball) without great force.
Example: Henry nodded the ball over the line
Definition: [noun] an act of nodding the head.
Example: at a nod from his father he left the room