Cock-up

[Sarah]

Another word for [screw-up] or [screwup]; to err.

[Greta]

A shambles. Sounds vulgar, but may not be; it may be a grouse shooting term. Customarily, shooters employ beaters to disturb birds on the ground and drive them into the air towards the guns. Normally one only shoots grouse hens, so if the beaters were by mistake to put up a grouse cock, they would warn the guns not to shoot by shouting Dont shoot! Its a cock up!
Can also be a transitive and intransitive verb.