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

Grace is sent into space on a one-way mission to stop the spread of an energy-consuming organism called Astrophage, which threatens to create a new Ice Age on Earth.

From The Wall Street Journal • Apr. 3, 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

In other words, once an intimate symbiotic relationship forms — in which at least one organism depends on another for survival — it’s locked in.

From Los Angeles Times • Feb. 10, 2026

Rarely, though, genetic material can cross from one organism to another—not between parent and child, but between two unrelated strangers.

From "The Gene" by Siddhartha Mukherjee

Related Words

• animal
• creature
• structure