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 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

Example Sentences

"Molecular markers are essential, but they capture only slices of biology. With behavior, you see the whole organism, continuously and non-invasively."

From Science Daily • Mar. 26, 2026

The Brunet lab has played a leading role in establishing the killifish as a model organism.

From Science Daily • Mar. 26, 2026

She added that the drugs did not provide effective coverage against a Gram-positive organism, which was the most likely pathogen causing the infection.

From BBC • Mar. 11, 2026

The organism is a methane producing member of a group of microbes known as Archaea.

From Science Daily • Feb. 28, 2026

“We’re going to open up these frogs and see what makes them tick. You never truly know how an organism works until you see what’s going on inside.”

From "The Science of Breakable Things" by Tae Keller

Related Words

• animal
• creature
• structure