# knock up

CEFR B2 · Phrasal verb

Source: https://englishreference.com/word/knock-up
Updated: 2026-04-24

## Definition

to wake someone by knocking on their door — often used in informal British English.

For teachers: to wake someone by knocking; also used informally to mean 'to create or produce something quickly' (e.g., 'knock up a report'). Marked British informal / slang.

## Examples

- He knocked up his friend at 7 AM.
- She had to knock up her roommate because they were late for work.
- The journalist knocked up a detailed report in under an hour, impressing the editor.

## Pitfalls

- Not "He knocked up." but "He knocked up his friend." — the phrasal verb requires an object to indicate who or what is being knocked up

## Usage notes

- typically followed by a person or thing being created or woken.
- Teaching tip: contrast with 'wake up' (more direct) and 'produce' (formal alternative); note the informal use of 'knock up' meaning 'create quickly' is limited to British English.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.