vang /vaŋ 
/ ▸ noun Sailing each of two guy ropes running from the end of a gaff to the deck. ▪ (also boom vang) a fitting used to pull a boat's boom down and help control the shape of the sail. – ORIGIN mid 18th century: variant of obsolete fang, denoting a gripping device, from Old Norse fang ‘grasp’, of Germanic origin.
EnglishOxford Dictionary of English
