Vang

1. A line leading from the gaff to either side of the deck, used to prevent the gaff from sagging.
2. One of a pair of ropes leading from the deck to the head of a spritsail. It steadies the sprit and can be used to control the sail's performance during a tack. The vang fall blocks are mounted slightly afore the main horse while rolling vangs are extra preventers which lead forward to keep the sail to leeward in heavy weather.
3. An abbreviation of boom vang or gaff vang.