Q: Here’s a question that’s been on my mind ever since my wife took a pregnancy test this morning. What’s the origin of the phrase “knocked-up”?
A: According to the Random House Historical Dictionary of American Slang, the phrase “knocked up,” meaning pregnant, first appeared in print in 1830! An 1860 slang dictionary defined the term this way: “Knocked up. … In the United States, amongst females, the phrase is equivalent to being enceinte.”
The Oxford English Dictionary traces the expression back as far as 1813 and says it’s of American origin. An OED citation from 1836 refers to slave women who are “knocked down by the auctioneer, and knocked up by the purchaser.”