Noun
guard consisting of a locking device that prevents a weapon from being fired
Source: WordNetDouble action is good for high-stress situations because it allows a mode of carry in which "draw and pull the trigger" is the only requirement—no safety catch release nor separate cocking stroke is required. Source: Internet
Was originally issued without a safety catch; instead, a half-cock notch on the cocking piece/firing pin assembly served this purpose. Source: Internet
The lever and the safety catch can also be clearly seen. Source: Internet