Source : Webster's Revised Unabridged Dictionary (1913)

Telephoto \Tel`e*pho"to\, a.
   Telephotographic; specif., designating a lens consisting of a
   combination of lenses specially designed to give a large
   image of a distant object in a camera of relatively short
   focal length.

Source : WordNet®

telephoto
     n : a photograph made with a telephoto lens [syn: {telephotograph}]