Definition of "heliograph" [he•li•o•graph]

• A device for transmitting messages by reflecting sunlight. (noun)
• A device for photographing the sun. (noun)
• To send (a message) by heliograph. (verb-transitive)
• To send a heliograph. (verb-intransitive)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The book that Uncle Ed sent us had in it a description of a heliograph, that is, an instrument for sending signals with flashes of sunlight."
• "If the Konor use a visual code, such as heliograph or semaphore, our energy scans would not necessarily detect them. ""
• "An industrial civilization does not easily go back to the Stone Age, but people adjust to what feels like the 19th-century frontier another favorite Heinlein setting: Ceramics replace metals, heliograph substitutes for radio, airdrops come in from outside."