[ aw-tuh-trof, -trohf ]

  1. any organism capable of self-nourishment by using inorganic materials as a source of nutrients and using photosynthesis or chemosynthesis as a source of energy, as most plants and certain bacteria and protists.

Compare Meanings

Click for a side-by-side comparison of meanings. Use the word comparison feature to learn the differences between similar and commonly confused words.

Origin of autotroph

1935–40; back formation from autotrophic;see auto-1, trophic

Other words from autotroph

  • au·to·troph·ic, adjective

Words Nearby autotroph Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Scientific definitions for autotroph


[ ôtə-trŏf′ ]

  1. An organism that manufactures its own food from inorganic substances, such as carbon dioxide and ammonia. Most autotrophs, such as green plants, certain algae, and photosynthetic bacteria, use light for energy. Some autotrophs, such as chemosynthetic bacteria, obtain their energy from inorganic compounds such as hydrogen sulfide by combining them with oxygen. Compare heterotroph.

Other words from autotroph

  • autotrophic adjective (ô′tə-trŏfĭk, -trōfĭk)

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.