he·​lio·​graph ˈhē-lē-ō-ˌgraf How to pronounce heliograph (audio)
: an apparatus for telegraphing by means of the sun's rays flashed from a mirror
heliograph transitive verb

Examples of heliograph in a Sentence

Recent Examples on the Web Obsidian is a primordial ooze, its natural history connected to the heliographs and the projection. Christopher Knight, Los Angeles Times, 20 Oct. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'heliograph.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


International Scientific Vocabulary

First Known Use

1877, in the meaning defined above

Time Traveler
The first known use of heliograph was in 1877

Dictionary Entries Near heliograph

Cite this Entry

“Heliograph.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/heliograph. Accessed 28 May. 2024.

More from Merriam-Webster on heliograph

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!