The Rice University Neologisms Database

Etymology : In paintball, the playing field is littered with obstacles, both inflatable and solid, that players take cover behind. These obstacles are called "bunkers," a term descended from World War I meaning "dug-out fortification," even though they are merely objects to hide behind rather than fully dug-out strong points. This change is an example of widening from a specific kind of cover to any cover point in general. The term underwent zero derivation to form a verb for ambushing someone behind one of these bunkers, which generally requires extreme close quarters conflict. As a result, "bunkering" someone is an act of skill because of the difficulty in getting so close to an enemy. Conversely, to "get bunkered" is something to be ashamed of.