Sailing with the wind coming from the stern or quarter of the boat.

A boat is sailing "off the wind" when it is not "close hauled" which means sailing at as close an angle as possible to the source of the wind. Anytime a boat is sailing an angle of greater than about 50 or 60 degrees from the direction of the wind it could be said to be sailing "off the wind". The names for points of sail that are off the wind are "reaching" and "running".

Sailing away from the wind, also downwind, reaching or running.

Toward leeward