Source : Webster's Revised Unabridged Dictionary (1913)

Collimate \Col"li*mate\, v. t. [imp. & p. p. {Collimated}; p. p.
   & vb. n. {Collimating}.] [See {Collimation}.] (Physics &
   Astron.)
   To render parallel to a certain line or direction; to bring
   into the same line, as the axes of telescopes, etc.; to
   render parallel, as rays of light.

Source : WordNet®

collimate
     v 1: make or place parallel to something; "They paralleled the
          ditch to the highway" [syn: {parallel}]
     2: adjust the line of sight of (an optical instrument)