1. (n.) A surface or object that reflects light or sound\.

2. (n.) Something having a polished surface for reflecting light or heat, as a mirror, a speculum, etc.

3. (n.) A reflecting telescope.

4. (n.) A device for reflecting sound.

Cassegrainian telescope Newtonian telescope OAO OSO astronomical observatory astronomical telescope cheval glass coelostat concave mirror convex mirror coronagraph coronograph distorting mirror glass hand mirror heliostat looking glass mirror observatory orrery pier glass planetarium radar telescope radio observatory radio telescope rear-view mirror refractor seeing glass shaving mirror spectrograph spectroheliograph spectrohelioscope spectroscope speculum telescope window mirror