blow (one's) brains out
slang To fatally shoot someone in the head. Ray blew the informant's brains out, just as the boss told him to.
blow someone's brains out
Sl. to kill someone with a gun. Careful with that gun, or you'll blow your brains out. Max was so depressed that he wanted to blow out his brains.
blow your/somebody’s ˈbrains out
(informal) kill yourself/somebody by shooting in the head: He was so depressed about his debts that he wanted to blow his brains out.