Definition from Wiktionary, the free dictionary
reflector (plural reflectors)
- Something which reflects heat, light or sound, especially something having a reflecting surface.
- A reflecting telescope.
- A small, often red, reflecting disk on the rear of a vehicle or bicycle that reflects the headlights of other vehicles.
See also 
- (telescope): refractor
- reflector (reflecting disk on the rear of a vehicle; chiefly a bicycle)
- first-person singular present passive indicative of reflectō