1. An individual form of life, such as a bacterium, protist, fungus, plant, or animal, composed of a single cell or a complex of cells in which organelles or organs work together to carry out the various processes of life.
2. A system regarded as analogous in its structure or functions to a living body: the social organism.
or′gan·ismal (-nĭzməl), or′gan·ismic (-mĭk) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.