/ ˌəʊvəˈhɪə(r); NAmE ˌoʊvərˈhɪr/ verb
( over·heard , over·heard / -ˈhɜːd; NAmE -ˈhɜːrd/) to hear, especially by accident, a conversation in which you are not involved :
[ vn ]
We talked quietly so as not to be overheard.
I overheard a conversation between two boys on the bus.
[ vn -ing ]
We overheard them arguing.
[ vn inf ]
I overheard him say he was going to France.
—compare eavesdrop