[ kol-uh-mey-ter ]
/ ˈkɒl əˌmeɪ tər /


  1. a fixed telescope for use in collimating other instruments.
  2. an optical system that transmits parallel rays of light, as the receiving lens or telescope of a spectroscope.
Physics. a device for producing a beam of particles in which the paths of all the particles are parallel.

Nearby words

  1. collieshangie,
  2. colligate,
  3. colligative,
  4. collimate,
  5. collimation,
  6. collin,
  7. collinear,
  8. collingswood,
  9. collingwood,
  10. collins

Origin of collimator

First recorded in 1815–25; collimate + -or2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for collimator

British Dictionary definitions for collimator


/ (ˈkɒlɪˌmeɪtə) /


a small telescope attached to a larger optical instrument as an aid in fixing its line of sight
an optical system of lenses and slits producing a nondivergent beam of light, usually for use in spectroscopes
any device for limiting the size and angle of spread of a beam of radiation or particles
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for collimator


[ kŏlə-mā′tər ]

A device that turns incoming radiation, such as light, into parallel beams. Simple collimators consists of a tube having a narrow, variable slit at one end and a convex lens at the other. Radiation entering the tube through the slit exits the lens in the form of parallel beams. Collimators are used to establish focal lengths of lenses and to measure the distance of distant objects whose position is known.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.