crack a fat

big fat

Complete, utter, total.

crack a crust

To make a living.

crack a smile

To smile, especially while attempting not to.

crack down

To take harsh action (against), as when enforcing a law more stringently than before.

crack of dawn

The first moment of daylight; the instant at which sunrise begins.

crack through

To penetrate

crack up

To laugh.

employ a steam engine to crack a nut

To carry out a simple task in an overcomplicated manner.