Half″cock′ (–kŏk′), v. t. [imp. & p. p.Halfcocked(–kŏkt); p. pr. & vb. n.Halfcocking.] To set the cock of (a firearm) at the first notch.
To go off halfcocked. (a) To be discharged prematurely, or with the trigger at half cock; — said of a firearm. (b) To do or say something without due thought or care.