heliometer

noun

he·​li·​om·​e·​ter ˌhē-lē-ˈä-mə-tər How to pronounce heliometer (audio)
: a visual telescope that has a divided objective designed for measuring the apparent diameter of the sun but also used for measuring angles between celestial bodies or between points on the moon
heliometric adjective
heliometrically adverb

Word History

Etymology

French héliomètre, from hélio- heli- entry 1 + -mètre -meter

First Known Use

1753, in the meaning defined above

Time Traveler
The first known use of heliometer was in 1753

Dictionary Entries Near heliometer

Cite this Entry

“Heliometer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/heliometer. Accessed 24 Jun. 2024.

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