Meaning of the word "running in" in English

What does "running in" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

running in

US /ˈrʌnɪŋ ɪn/
UK /ˈrʌnɪŋ ɪn/

Phrasal Verb

1.

to break in a new engine or vehicle by driving it carefully at moderate speeds for a period of time

Example:
You need to spend some time running in the new car before driving it at high speeds.
The mechanic advised me to run in the engine for the first 500 miles.
2.

to enter a place quickly or unexpectedly

Example:
The children came running in from the garden when it started to rain.
He suddenly ran in and announced the good news.