Luffing up and falling away
Luffing up and falling off are terms used in sailor language .
The change of direction of a sailing ship to windward is called luffing . This is a change of course of the ship higher up the wind, so that the wind comes in more forward (more from the front). The luffing ends when the sails keel (the sails " flap " in the wind).
The opposite of luffing is falling off.
When dropping the change in direction is called a sailing vessel to leeward. This is a change in course of the ship away from the wind, so that the wind is more from the side or more from the rear.
The windward side (side of the ship on which the wind blows) does not change when luffing up or falling.