Word of the day – Collimate

Word of the Day : May 4, 2020


verb KAH-luh-mayt


  • to make parallel

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.”


Amazingly, some astrophysical jets—streams of charged particles collimated and accelerated over astronomical distances—also exhibit a helical structure.” — Mario Livio, The Huffington Post, 6 Dec. 2017

Multiple sessions will demonstrate how to set up different kinds of telescopes.… Another session will be held on collimating the reflector, which means aligning everything so it works well.” — Rebecca Hazen, The Houston Chronicle, 1 Feb. 2018

Merriam-Webster Word of the Day