Green’s Dictionary of Slang

break a leg v.

1. [17C–18C] (also break one’s leg) of a womanizing man, to become father to a child, whether one wishes to or not.

2. [late 17C+] (also break one’s leg) to become pregnant out of wedlock; often ext. as break a/one’s leg above the knee.

3. [late 19C–1940s] (also break one’s knee) of a young woman, to lose one’s virginity, to be seduced.

4. [mid-19C] to seduce.

5. [1900s–30s] (US) to be arrested.

6. [1910s–50s] (orig. US) to hurry.