1. break a leg - Interjection
2. break a leg - Phrase
break a leg!
(idiomatic) Said to someone wishing they perform well in a theatrical production or comparable endeavor.
Synonym: (opera) toi, toi, toi
Go out there and break a leg tonight. Put on a great show!
I told my friend to break a leg, before she went on stage.
In this business you break a leg and 150 other people are out of work while production is shut down. It's not like you were an accountant and could still work with your leg in a cast. Ken Curtis
Break a leg, Sp3ccylad, but just remember: quickies with Blue Gal are always longer than you plan for and shorter than you wish. Source: Internet