A lovely little phrase with a dual meaning, both of which were coined by English speaking nations.

In the UK, it means "to knock on one's door in order to rouse them from their slumber". However, in the US, the younger and slightly more risqué cousin of the UK, it is a form of the verb phrase 'to knock up', which refers to the act of impregnating someone.

Remember to be mindful of your speech when travelling abroad.
British Man: "When would you like me to knock you up tommorrow?"
American Woman: "Who's gonna do what now!?"
by TheNineteenth January 29, 2015
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British:
To wake you up tomorrow. It goes back to the days in before alarms where they used to come around and knock on your door to wake you up. Moden UK or british type hotel clerks will still use the saying.
I'll knock you up in morning, we'll suck a quick fag and be off.
by Pokerman11 February 1, 2008
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In America it means impregnated, while in the UK it means rudely woken up.
The dual meaning of, “knock you up” is displayed in this Frasier script.

Daphne Moon: Your father knocked me up bright and this morning.
Frasier Crane: My father did what to you!?
Daphne: He knocked me up. In England it means to be woken up. What does mean here?
Frasier: Oh, uhh nothing…
by Biden is a dick December 27, 2022
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A saying from England that means to knock on your door. If your related to somebody from england, tell them that and see what they say.
English Man: Can I knock you up? American Lady: NO! YOU CREEP
by Badasscrackermotherfucker August 21, 2011
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