Run in Meaning in English
expression
Definition
'Run in' can mean to meet someone by chance, especially unexpectedly, or to operate a new engine carefully to make it work better. Sometimes in the UK, it can also mean to quickly arrest or take someone to the police station.
Usage & Nuances
Informal for chance meetings ('run in to someone'). 'Run in' as engine break-in is mostly UK/Commonwealth; in American English, 'break in' is more common. Rarely, police slang for arrest. Don't use 'run in' when you mean 'enter quickly'—that would be 'run into'.
Example Sentences
I ran in to my old teacher at the supermarket.
basic
Remember to run in the car gently for the first 1,000 miles.
basic
The police ran him in for questioning.
basic
Funny, I just ran in to Emma at the train station this morning.
natural
You should always run in a new engine to extend its life.
natural
They ran him in after he caused a scene at the pub.
natural