cap over the windmill

bust a cap

To fire a weapon; to shoot with a gun.

cap in hand

In a humble and respectful manner.

cap it all off

To finish or complete something; to add a finishing touch.

considering cap

An imaginary hat worn to aid careful thought or deliberation.

feather in one's cap

An accomplishment; particularly one that is flaunted or boasted of.

set one's cap at

To choose a man as a potential husband (for a girl).

thinking cap

A metaphorical state of focused thinking or concentration, invoked to encourage problem-solving.

throw one's cap over the windmill

To act in a bizarre, eccentric or immoral manner.