The story
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: The best possible combination of perks, stats, and modifiers (like barrels, magazines, masterworks) for a specific weapon or piece of gear, maximizing its potential for a particular use, such as Player vs. Environment (PvE) or Player vs. Player (PvP); the objectively optimal set that makes a weapon exceptionally powerful and highly sought after by players who farm for them. Full definition →
Etymology from Wiktionary, CC BY-SA 4.0.