reflector
n. B2 Upper Intermediate US //ɹɪˈfɫɛktɝ// UK //ɹɪflˈɛktɐ// re·flec·tor
n. a surface or object that sends light, heat, or sound back to where it came from. You often see them on bicycles to help you be seen at night.
n. a surface or device that redirects light, sound, or heat back toward its source. Often used in safety equipment or optical systems to enhance visibility.
The cyclist wore a bright yellow reflector on his back.
The car's headlights were blocked by a thick layer of fog, but the reflector on the road sign still helped us see the curve.
Engineers designed the satellite's surface to act as a perfect reflector, ensuring that the signal returned to Earth with minimal loss of strength.
From reflect + -or.