A friend and I started randomly wondering about this the other night. How did the phrase “knocked up” come to be slang for pregnant? When did it come into common use? Anyone know?
I imagine it has something to do with the motions of intercourse causing the bed to “jiggle”, and making a knocking sound as it hits the wall over and over. 'Course, that’s just pure speculation, but I hate seeing a GQ thread with zero replies.
Well, like so many percussive verbs, “knocking” is slang for intercourse. One of the many slang expressions for a brothel is a knocking shop.
From there to “knocked up” is a pretty short and obvious step.
knocked up, meaning to inujure, incapacitate, etc is in the OED by 1737.
knocked up meaning to make pregnant, appears in print in 1813. There are cites from the mid-1800’s which would indicate that this meaning was common in the US but not in England.
knock as slang for intercourse appears in the OED in 1598.
My dad used to say “up a stump.” That’s even more opaque…
Anyway, I wonder how many Britishers have gotten into trouble by saying they knocked up someone only to mean that they went to their house?