[ awr-guh-niz-uhm ]
See synonyms for: organismorganisms on

  1. a form of life composed of mutually interdependent parts that maintain various vital processes.

  2. a form of life considered as an entity; an animal, plant, fungus, protistan, or moneran.

  1. any organized body or system conceived of as analogous to a living being: the governmental organism.

  2. any complex thing or system having properties and functions determined not only by the properties and relations of its individual parts, but by the character of the whole that they compose and by the relations of the parts to the whole.

Origin of organism

First recorded in 1655–65; organ + -ism

Other words for organism

Other words from organism

  • or·gan·is·mic, or·gan·is·mal, adjective
  • or·gan·is·mi·cal·ly, adverb
  • su·per·or·gan·ism, noun

Words that may be confused with organism Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use organism in a sentence

British Dictionary definitions for organism


/ (ˈɔːɡəˌnɪzəm) /

  1. any living biological entity, such as an animal, plant, fungus, or bacterium

  2. anything resembling a living creature in structure, behaviour, etc

Derived forms of organism

  • organismal or organismic, adjective
  • organismally, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for organism


[ ôrgə-nĭz′əm ]

  1. An individual form of life that is capable of growing, metabolizing nutrients, and usually reproducing. Organisms can be unicellular or multicellular. They are scientifically divided into five different groups (called kingdoms) that include prokaryotes, protists, fungi, plants, and animals, and that are further subdivided based on common ancestry and homology of anatomic and molecular structures.

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