reflector

noun7

1. •
   Something which reflects heat, light or sound, especially something having a reflecting surface.

   • Then came a maid with hand-bag and shawls, and after her a tall young lady. She stood for a moment holding her skirt above the grimy steps,[…], and the light of the reflector fell full upon her. — 1897
2. •
   A small, often red, reflecting disk on the rear of a vehicle or bicycle that reflects the headlights of other vehicles.
3. •
   A safety reflector.
4. •
   Something that is reflective (indicative) of something else.
5. •
   A reflecting telescope.
6. •
   One who reflects on something; one who thinks or considers at length.

   • Most reflectors on leadership are comfortable thinking of "ethical" and "unethical" as modifiers of leadership. — 1993
7. •
   A pattern which can change the direction and/or offset of an oncoming spaceship without being destroyed.