listen in phrasal verb (
see also listen)
1. to listen to a broadcast on the radio
listen in to
I must remember to listen in to the news. ⇒
tune in(1)
2. to listen to someone’s conversation when they do not want you to
listen in on It sounded like someone was listening in on us. [TahlilGaran] Dictionary of Contemporary English ▲
listen in v. 1. To listen to a radio broadcast.
We found them listening in to the president's speech. 2. To listen to the talk of others, often to talk that is not intended for your ears; eavesdrop.
When Mary talked to her boyfriend on the telephone, her little brother listened in. [TahlilGaran] English Idioms Dictionary ▲