What is another word for listen in on?
Pronunciation: [lˈɪsən ɪn ˈɒn] (IPA) 
"Listen in on" typically refers to the act of secretly or surreptitiously overhearing a conversation or communication. There are several synonyms for this phrase, including eavesdrop, spy on, overhear, and monitor. Eavesdrop is commonly used to describe the act of covertly listening to a conversation without the knowledge of the speakers. To spy on someone is to secretly observe them or their activities, often with the intention of gathering information. Overhear, on the other hand, simply means to unintentionally hear something while in proximity to the speakers. Lastly, to monitor someone is to keep tabs on their communications or activities, typically through surveillance or electronic means.
