By Your Leave
Definition: a request for permission
Why I Looked It Up
I used to say this in Navy boot camp and A School – when you approached an officer from behind (so, you were walking faster than they were), you would have to salute and say “By your leave, sir/ma’am.” I think this might have been a training thing – I’m not sure this continued out in the fleet (I was in the Reserves).
I encountered the phrase again in a book about the history of oil, where it was used by a politician in some form of, “We will never say ‘by your leave’ to any other nation!”
Those two usages make me think that “by your leave” intones some form of inherent submissiveness.