Meaning

noun a hazard on a golf course

noun a large container for storing fuel

noun a fortification of earth; mostly or entirely below ground

originThe origin of the noun is uncertain; the earliest sense is sense 7.1 (“box or chest, the lid of which serves as a seat”), from Scots bunker (“bench; pew; window-seat; sand pit (especially in golf); coal receptacle; sleeping berth, bunk”), from Early Scots bunker, bunkur, bonker (“a chest or box, often serving as a seat”), probably from Old Norse bunki (“a heap”) (probably whence bunk (“sleeping…

Etymology from Wiktionary, CC BY-SA 3.0