sprain (one's) ankle
1. Literally, to injure ligaments in one's ankle by wrenching or suddenly twisting them. At first I thought I had only sprained my ankle, but it turns out I actually broke a few bones when I fell like that.
2. obsolete euphemism To be or become pregnant. I heard the poor lass was taken in by a rake and ended up spraining her ankle.
sprain one's ankle
to become pregnant. She has, ah, sprained her ankle. From the looks of her, she must have sprained her ankle some months ago.