Ah, this must be a British vs American English thing, thanks for the info.

Yes I meant it in this sense: "If you knock something up, you make it or build it very quickly, using whatever materials are available."

https://www.collinsdictionary.com/dictionary/english/knock-u...

Heh, thanks, yes, your meaning was obvious from context alone. I'm really surprised not to have encountered the British usage before (or so rarely). Maybe owing to potential for huge misunderstandings. ("Jimmy knocked her up" -> woke in the night || impregnated and abandoned.)

TIL