gossip mirror UK /ˈɡɒsɪp ˌmɪɹə/US /ˈɡɑsəp ˌmɪɹəɹ/ noun1 •A mirror or pair of mirrors mounted outside a window, allowing the viewer to see along a street while remaining indoors.Röschen was keeping watch at the gossip-mirror in the library window, and would give warning as soon as she saw the great R and his Hindoo adept in the distance. — 1891 formsgossip mirrors · gossip-mirrors