break down

big break

A breakthrough, especially the first big hit of a previously unknown performer or performers in the entertainment industry.

break a leg

Good luck!; Do your best!; Said to someone wishing they perform well in a theatrical production or comparable endeavor.

break a sweat

To put effort into something.

break cover

To disclose one's real thoughts and intentions.

break even

To neither gain nor lose money.

break gates

To enter an Oxford or Cambridge college enclosure after the hour to which a student has been restricted.

break in

To reach a state of functioning more smoothly through use or wear; to cause (something, or someone, new) to undergo this change.

break into

To enter illegally or by force, especially in order to commit a crime.