organism

American  

[awr-guh-niz-uhm] / ˈɔr gəˌnɪz əm /

noun

• organisms
  plural

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

Derived Forms

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

Inflected Forms

Nouns

• organisms
  plural

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

See Examples For:

organism organisms

Earlier in its evolutionary history, the organism appears to have possessed two eyes or at least two groups of cells capable of detecting light.

From Science Daily ● Jul. 26, 2026

Mendelsohn treated the parts of the building as if they were one thing, a single living organism.

From The Wall Street Journal ● Jul. 24, 2026

The term is less taxonomically specific and more of a catchall, used to refer to any photosynthesizing organism that isn’t a plant.

From Slate ● Jun. 27, 2026

In ecology, a niche refers to the role an organism plays within its environment, including what it eats, where it lives, and how it interacts with other species.

From Science Daily ● Jun. 22, 2026

In Darwin's scheme, the rate of change of an organism was generally fixed, while the rate of natural selection could be amplified to accelerate evolution or dampened to decelerate it.

From "The Gene" by Siddhartha Mukherjee

That question matters because microbial organisms dominated Earth for roughly 90 percent of the planet's history.

From Science Daily ● Aug. 17, 2026

It also demonstrates how research on unusual organisms can expose biological processes that have remained hidden despite potentially operating for hundreds of millions of years.

From Science Daily ● Aug. 17, 2026

By learning which environments preserve ancient organisms on Earth, scientists may become better equipped to recognize possible signs of life elsewhere.

From Science Daily ● Aug. 17, 2026

The microscopic organisms can look like blue-green paint, scum or greenish-brown discolouration.

From BBC ● Aug. 12, 2026

And that really means everything, from trees and birds to single-celled organisms and viruses.

From "Meltdown" by Deirdre Langeland

Related Words

• animal
• creature
• structure