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

In Darwinian evolution, organisms that are well-adapted to their environments flourish and crowd out those that aren’t. James Degregori, STAT, "Using the principles of evolution to treat and prevent cancer," 27 June 2018 The organisms can spread by hitching a ride on boats and other equipment, including trailers, anchors, live wells, buckets and bilges. Paul A. Smith, Milwaukee Journal Sentinel, "Smith: Quagga mussels, Eurasian water milfoil, spiny water fleas ... and a catchy tune," 20 June 2018 According to a consortium of researchers from the Deep Carbon Observatory (DCO), the massive subterranean biosphere contains enough organisms to eclipse Earth's oceans nearly twice over. Sam Blum, Popular Mechanics, "Vast Ecosystem of Underground Organisms Holds More Life Than Earth's Oceans," 11 Dec. 2018 If your asparagus bed does become infected by disease organisms, your best option is to start a new bed in a distant part of the garden, using newly purchased or grown plants. The Editors, Good Housekeeping, "How to Grow Garden-Fresh Asparagus," 19 Aug. 2018 Tissue samples taken from the whale shark indicate it was infected by the Karenia brevis organism, which produces the brevetoxins that can harm and, in some cases, kill sea life. Madeline Farber, Fox News, "Dead whale shark in Florida washes up on beach; red tide likely killer," 27 July 2018 Geneticists characterize different groups of dogs, or any organisms, on the basis of differences in their DNA, showing how closely they are related. James Gorman, New York Times, "The Lost Dogs of the Americas," 5 July 2018 Clades are organisms that have evolved from a common ancestor. Chris Ciaccia, Fox News, "'Survival of the laziest' is key to avoiding extinction," 22 Aug. 2018 The classic textbook definition, known as the biological species concept, is a group of organisms that only produce fertile offspring with one another. Bridget Alex, Discover Magazine, "What Defines A Species?," 17 Aug. 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

18 Feb 2019

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

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