go off at half cock Definition

cock¹
noun

1. A male bird, especially an adult male chicken.
2. A stopcock.
3. The hammer of a gun which, when raised and let go by the trigger, produces the discharge.
4. coarse slang
The penis.
5. coarse slang
Nonsense.
6. slang
A pal, usually used as a form of address.

verb cocked, cocking

tr & intr
1. To lift; to stick up.
2. To turn in a particular direction.

Example: cock an ear towards the door
3. To draw back the hammer of a gun.
4. To set (one's hat) at an angle.

Idiom: go off at half cock

To begin too soon, without being fully prepared.

Etymology: Anglo-Saxon cocc.

Phrasal Verb: cock something up

To make a mess of it; to do it badly. See also cock-up.
Example: He really cocked up his exams