(idiomatic, intransitive) To be crazy or eccentric.

(idiomatic) To raise one's clenched fists in front of one's body and stand in a threatening or defiant manner, in preparation for a fistfight.

(idiomatic) To create a difficult situation whose unpleasant consequences one must now endure.

(idiomatic) To make an extra effort, so as to help or hinder.

(idiomatic) To become serious, organized, worthwhile, etc.

(idiomatic) To keep quiet; to keep a secret; to not tell.

(idiomatic) To make one's best effort or attempt; to try as hard as possible.

(idiomatic) To experience the consequences of one's actions.

(idiomatic) To be organized; to have one's affairs in order; specifically, to have a multi-person effort coordinated towards the exact same goal.

(idiomatic) Disturbingly confident, unacceptably cocky. / Used other than figuratively or idiomatically: Too large to fit into one's pants.