Meaning of the word "in league" in English

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

in league

US /ɪn liːɡ/
UK /ɪn liːɡ/

Idiom

working together with someone, especially secretly or for an illegal or dishonest purpose

Example:
The two companies were suspected of being in league to fix prices.
He claimed that the police were in league with the criminals.