1 B1 idiomatic informal
(British) To wake someone by knocking on their door.
"Could you knock me up at seven tomorrow morning? I don't have an alarm."
separable
knock up
B1 informal separable transitive
A versatile phrasal verb with distinct British and North American meanings, including waking someone, making something quickly, or (informally) making someone pregnant.
In plain English
To wake someone up by knocking (British), or to make something fast, or (slang) to make a woman pregnant.
What does "knock up" mean?
4 meanings, ordered from most common to least. Color-coded by CEFR level.
2 B1 idiomatic informal
(British) To prepare or make something quickly, especially food.
"She knocked up a fantastic pasta dish in under twenty minutes."
separable
3 B2 idiomatic slang
(North American, vulgar slang) To make a woman pregnant.
"He knocked her up and then refused to take any responsibility."
separable
4 B2 idiomatic informal
(British, informal) To tire someone out completely; to exhaust.
"That long shift at the hospital really knocked me up."
separable
Literal vs figurative
Words literally mean
To knock in an upward direction.
Actually means
To wake someone up by knocking (British), or to make something fast, or (slang) to make a woman pregnant.
Usage tip
Strongly regional: in British English, 'knock up' means to wake someone by knocking or to prepare something quickly. In North American English, it almost exclusively means to make someone pregnant (vulgar/slang). ESL learners should be aware of this significant regional difference to avoid embarrassment.
Words that pair with "knock up"
Natural word combinations native speakers use most often.
door meal breakfast early quickly friend
How to conjugate "knock up"
The five tense forms you'll use most often.
Base
knock up
I/you/we/they
3rd person
knocks up
he/she/it
Past simple
knocked up
yesterday
Past participle
knocked up
have + pp
-ing form
knocking up
continuous
Hear "knock up" in the wild
Listen to native speakers using "knock up" in real YouTube videos — click a clip to watch it on Looplines.
Keep exploring
Jump to every phrasal verb built on the same verb, particle, or level.