collimate

verb

col·​li·​mate ˈkä-lə-ˌmāt 

collimated; collimating

transitive verb

: to make parallel

collimate light rays

collimation

ˌkä-lə-ˈmā-shən 

noun

Did you know?

One might expect a science-y word like collimate to have a straightforward etymology, but that's not the case. Collimate comes from Latin collimāre, a misreading of the Latin word collineāre, meaning "to direct in a straight line." The erroneous collimāre appeared in some editions of the works of ancient Roman statesman Cicero and scholar Aulus Gellius. The error was propagated by later writers—most notably by astronomers, such as Johannes Kepler, who wrote in Latin. And so it was the spelling collimate, rather than collineate, that passed into English in the 19th century as a verb meaning "to make (something, such as light rays) parallel."

Examples of collimate in a Sentence

Recent Examples on the Web

But black holes produce their own radiation, especially high-energy X-rays and gamma-rays, which shoot out from the star in the form of tightly collimated... —Newsweek, 14 Mar. 2018

Word History

Etymology

Latin collimatus, past participle of collimare, manuscript variant of collineare to make straight, from com- + linea line

First Known Use

1878, in the meaning defined above

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Kids Definition

collimate

verb

col·​li·​mate ˈkäl-ə-ˌmāt 

collimated; collimating

: to make (as rays of light) parallel

Medical Definition

collimate

transitive verb

col·​li·​mate ˈkäl-ə-ˌmāt 

collimated; collimating

: to make (as rays of light) parallel

collimation

ˌkäl-ə-ˈmā-shən 

noun