Halfcock

Half´cock`

(~kǒk`)
v. t.1.To set the cock of (a firearm) at the first notch.[imp. & p. p. Halfcocked(-kǒkt); p. pr. & vb. n. Halfcocking.]
To go off half-cocked
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.