The Collaborative International Dictionary of English v.0.48:

Reflector \Re*flect"or\ (-[~e]r), n. [Cf. F. r['e]flecteur.]
   1. One who, or that which, reflects. --Boyle.
      [1913 Webster]

   2. (Physics)
      (a) Something having a polished surface for reflecting
          light or heat, as a mirror, a speculum, etc.
      (b) A reflecting telescope.
      (c) A device for reflecting sound.
          [1913 Webster]

WordNet (r) 3.0 (2006):

reflector
    n 1: device that reflects radiation
    2: optical telescope consisting of a large concave mirror that
       produces an image that is magnified by the eyepiece; "Isaac
       Newton invented the reflecting telescope in 1668" [syn:
       reflecting telescope, reflector]