organism

American  

[awr-guh-niz-uhm] / ˈɔr gəˌnɪz əm /

noun

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.

3. any organized body or system conceived of as analogous to a living being.

   the governmental organism.

4. 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.

   Synonyms:

   structure, entity, network, organization

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organism British  

/ ˈɔːɡəˌnɪzəm /

noun

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

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

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organism Scientific  

/ ôr′gə-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.

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Other Word Forms

• organismal
  adjective
• organismally
  adverb
• organismic
  adjective
• organismically
  adverb
• superorganism
  noun

Etymology

Origin of organism

First recorded in 1655–65; organ + -ism

Explanation

An organism is a living thing that can function on its own. That includes your pet guppy, the tree in your backyard, and — of course — you. While the word organism typically indicates an actual living thing, you can also use organism to refer to anything that acts or functions like a living thing. For example, the social scene at a high school might be described as "a social organism" because it seems to have a mind of its own — like a living thing or even a vicious animal, depending on where one falls on the popularity scale.

Example Sentences

In the 1940s, University of Chicago economist Frank H. Knight devised a thought experiment called the Crusonia plant: a miraculous organism that, once planted, yields fruit year after year without any effort.

From The Wall Street Journal • May 27, 2026

Unlike earlier approaches focused on individual tissues or organs, MouseMapper provides an integrated whole-body analysis system that can identify disease hotspots throughout an organism.

From Science Daily • May 23, 2026

The multi-eyed organism will serve as the centerpiece of “the N.E.S.T.,” an EIT-designed section of Meow Wolf’s new 26,000-square-foot immersive exhibition space.

From Los Angeles Times • May 20, 2026

Kevin Monsalvo, 26, has followed in the footsteps of Granados and said things are different for him since he learned more about the organism threatened with extinction.

From Barron's • May 7, 2026

Obviously, then, there is little basis for the hope or belief that the gonads of any organism are shielded from chemicals in the environment.

From "Silent Spring" by Rachel Carson

Related Words

• animal
• creature
• structure