# Origins of the phrase "knocked up?"

**URL:** <https://boards.straightdope.com/t/origins-of-the-phrase-knocked-up/65987>\
**Category:** Factual Questions\
**Created:** [May 20, 2001, 9:50am UTC](https://boards.straightdope.com/t/origins-of-the-phrase-knocked-up/65987 "2001-05-20T09:50:58Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Llewwellyn](https://avatars.discourse-cdn.com/v4/letter/l/e0b2c6/32.png) [@Llewwellyn](https://boards.straightdope.com/u/Llewwellyn)\
**Post date:** [May 20, 2001, 9:50am UTC](https://boards.straightdope.com/t/origins-of-the-phrase-knocked-up/65987/1 "2001-05-20T09:50:58Z")

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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?

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**Author:** ![SPOOFE](https://avatars.discourse-cdn.com/v4/letter/s/c5a1d2/32.png) [@SPOOFE](https://boards.straightdope.com/u/SPOOFE)\
**Post date:** [May 20, 2001, 10:32am UTC](https://boards.straightdope.com/t/origins-of-the-phrase-knocked-up/65987/2 "2001-05-20T10:32:20Z")

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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.

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**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\
**Post date:** [May 20, 2001, 4:12pm UTC](https://boards.straightdope.com/t/origins-of-the-phrase-knocked-up/65987/3 "2001-05-20T16:12:34Z")

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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.

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**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\
**Post date:** [May 20, 2001, 6:30pm UTC](https://boards.straightdope.com/t/origins-of-the-phrase-knocked-up/65987/4 "2001-05-20T18:30:55Z")

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_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.

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**Author:** ![Myron\_Van\_Horowitzski](https://avatars.discourse-cdn.com/v4/letter/m/9de053/32.png) [@Myron\_Van\_Horowitzski](https://boards.straightdope.com/u/Myron_Van_Horowitzski)\
**Post date:** [May 22, 2001, 5:07pm UTC](https://boards.straightdope.com/t/origins-of-the-phrase-knocked-up/65987/5 "2001-05-22T17:07:32Z")

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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?