or·​gan·​ism | \ˈȯr-gə-ˌni-zəm \

Definition of organism 

1 : a complex structure of interdependent and subordinate elements whose relations and properties are largely determined by their function in the whole the nation is not merely the sum of individual citizens at any given time, but it is a living organism, a mystical body … of which the individual is an ephemeral part— Joseph Rossi

2 : an individual constituted to carry on the activities of life by means of parts or organs more or less separate in function but mutually dependent : a living being a multicellular organism

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Other Words from organism

organismic \ˌȯr-​gə-​ˈniz-​mik \ or less commonly organismal \ˌȯr-​gə-​ˈniz-​məl \ adjective
organismically \ˌȯr-​gə-​ˈniz-​mi-​k(ə-​)lē \ adverb

Examples of organism in a Sentence

A human being is a complex organism.

Recent Examples on the Web

Within a week, the cells were growing into organoids—small blobs of tissue similar to organs in mature organisms. Diana Gitig, Ars Technica, "Researchers grow a placenta in a petri dish," 4 Dec. 2018 One satellite will look at the color of oceans to determine the health of the planet’s waters, while another will send algae into space to see what the space environment does to these organisms. Loren Grush, The Verge, "Watch SpaceX launch its biggest crop of satellites yet with a twice-used rocket," 3 Dec. 2018 The technology has attracted controversy—and even a failed attempt to ban its use globally—because, if released in the wild, organisms carrying gene drives might be hard to contain. Ewen Callaway, Scientific American, "Controversial CRISPR “Gene Drives” Tested in Mammals for the First Time," 10 July 2018 Impossible Burger has an ingredient that comes from recombinant organisms that is artificial that might put some people off. Angela Chen, The Verge, "These are the technology advances that could end animal farming," 9 Nov. 2018 So while one organism might construct a more accurate representation of reality, that representation doesn’t enhance its survivability. Tim Folger, Discover Magazine, "How Quantum Mechanics Lets Us See, Smell and Touch," 24 Oct. 2018 The reservoir, or organism that the viruses naturally live and reproduce in, is still unknown. Kimberly Hickok, Fox News, "Scientists discover a sixth species of Ebola virus — in bats," 27 Aug. 2018 Almost all organisms on Earth do, from animals and plants to bacteria and fungi, but at some point in their history, placental mammals like us stopped producing enzymes that heal DNA with light. Robbie Gonzalez, WIRED, "DNA-Repairing Sunscreen: Legit or Not?," 2 July 2018 Moist nooks and crannies full of dead skin cells become the perfect breeding ground for organisms that can cause skin infections, according to the Cleveland Clinic. Caroline Picard, Good Housekeeping, "Test Your Housekeeping Knowledge: How Gross Are Your Cleaning Habits?," 10 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'organism.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of organism

circa 1774, in the meaning defined at sense 1

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Statistics for organism

Last Updated

9 Dec 2018

Look-up Popularity

Time Traveler for organism

The first known use of organism was circa 1774

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More Definitions for organism



English Language Learners Definition of organism

: an individual living thing

: a system with many parts that depend on each other and work together


or·​gan·​ism | \ˈȯr-gə-ˌni-zəm \

Kids Definition of organism

: a living thing made up of one or more cells and able to carry on the activities of life (as using energy, growing, or reproducing)


or·​gan·​ism | \ˈȯr-gə-ˌniz-əm \

Medical Definition of organism 

: an individual constituted to carry on the activities of life by means of organs separate in function but mutually dependent : a living being

Other Words from organism

organismic \ˌȯr-​gə-​ˈniz-​mik \ also organismal \-​məl \ adjective
organismically \-​mi-​k(ə-​)lē \ adverb

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More from Merriam-Webster on organism

Rhyming Dictionary: Words that rhyme with organism

Spanish Central: Translation of organism

Nglish: Translation of organism for Spanish Speakers

Britannica English: Translation of organism for Arabic Speakers

Comments on organism

What made you want to look up organism? Please tell us where you read or heard it (including the quote, if possible).


living or existing for a long time

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