col·​li·​ma·​tor ˈkä-lə-ˌmā-tər How to pronounce collimator (audio)
: a device for producing a beam of parallel rays (as of light) or for forming an infinitely distant virtual image that can be viewed without parallax
: a device for obtaining a beam (as of particles) of limited cross section

Word History

First Known Use

1865, in the meaning defined at sense 1

Time Traveler
The first known use of collimator was in 1865

Dictionary Entries Near collimator

Cite this Entry

“Collimator.” Dictionary, Merriam-Webster, Accessed 3 Dec. 2023.

Medical Definition


col·​li·​ma·​tor ˈkäl-ə-ˌmāt-ər How to pronounce collimator (audio)
: a device for obtaining a beam of radiation (as X-rays) of limited cross section

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