pho·​to·​au·​to·​troph ˌfō-tō-ˈȯ-tə-ˌtrȯf How to pronounce photoautotroph (audio)
plural photoautotrophs
: a photosynthetic organism (such as a green plant or a cyanobacterium) that utilizes energy from light to synthesize organic molecules
Green plants that convert carbon dioxide into carbohydrates in the presence of sunlight are called photoautotrophs, and they are the primary producers in most marine and terrestrial ecosystems.James J. Childress et al.

Word History

First Known Use

1939, in the meaning defined above

Time Traveler
The first known use of photoautotroph was in 1939

Dictionary Entries Near photoautotroph

Cite this Entry

“Photoautotroph.” Dictionary, Merriam-Webster, Accessed 2 Mar. 2024.

Medical Definition


pho·​to·​au·​to·​troph ˌfōt-ō-ˈȯt-ə-ˌtrōf How to pronounce photoautotroph (audio)
: a photoautotrophic organism
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