listen in

verb

listened in; listening in; listens in

intransitive verb

1

: to tune in to or monitor a broadcast

2

: to listen to a conversation without participating in it

especially : eavesdrop

listener-in

ˌli-sᵊn-ər-ˈin 

ˌlis-nər-

noun

Synonyms of listen in

• eavesdrop (on)
• hear
• monitor
• spy
• overhear

Examples of listen in in a Sentence

it's not polite to listen in on other people's private conversations

Recent Examples on the Web

Most of that unfolds in fairly predictable fashion, starting when Aubrey invites David for a drink after work and Sara listens in on his phone app. — David Rooney, HollywoodReporter, 3 Aug. 2026

Sytkas and Solderini claim that an attacker could even activate camera feeds and listen in through device microphones. — Kim Key, PC Magazine, 30 July 2026

As Perez spoke glowingly about Kansas City, the Royals contingent listened in a celebratory mood. — Kansas City Star, 26 July 2026

For the past six years, Project CETI (Cetacean Translation Initiative) has been listening in on the chatter of sperm whales in the Eastern Caribbean off the coast of the island of Dominica. — Laura Baisas, Popular Science, 22 July 2026

Word History

First Known Use

1905, in the meaning defined at sense 1

Kids Definition

listen in

verb

1

: to listen to a broadcast

2

: eavesdrop