If you nod, you move your head downwards and upwards to show that you are answering 'yes' to a question, or to show agreement, understanding, or approval.

If you nod in a particular direction, you bend your head once in that direction in order to indicate something or to give someone a signal.

If you nod, you bend your head once, as a way of saying hello or goodbye.

In football, if a player nods the ball in a particular direction, they hit the ball there with their head.

If you give someone the nod, you give them permission to do something.

If a proposal is accepted on the nod, it is accepted without being questioned or argued about.