organism

noun

or·​gan·​ism ˈȯr-gə-ˌni-zəm How to pronounce organism (audio)
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
organismic adjective
or less commonly organismal
organismically adverb

Examples of organism in a Sentence

A human being is a complex organism.
Recent Examples on the Web
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One way the Plant Health Care Report helps is by tracking units that measure how warmth is accumulating as days grow longer, affecting the development of plants and other organisms. Beth Botts, Chicago Tribune, 11 Apr. 2026 Wet conditions also favor the spread of disease organisms. Kim Toscano, Southern Living, 10 Apr. 2026 British scientists have packed a container full of worms aboard Northrop Grumman's Cygnus XL cargo vehicle, to be launched by a SpaceX Falcon 9 rocket on Friday morning (April 10), to study the effects of long-duration spaceflight on biological organisms. Tereza Pultarova, Space.com, 9 Apr. 2026 Caenoplana variegata preys on small soil-dwelling organisms such as woodlice, insects and spiders that contribute to soil health. Hanna Wickes, Miami Herald, 9 Apr. 2026 See All Example Sentences for organism

Word History

First Known Use

circa 1774, in the meaning defined at sense 1

Time Traveler
The first known use of organism was circa 1774

Browse Nearby Words

Cite this Entry

“Organism.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/organism. Accessed 12 Apr. 2026.

Kids Definition

organism

noun
or·​gan·​ism ˈȯr-gə-ˌniz-əm How to pronounce organism (audio)
1
: something having many related parts that function together as a whole
2
: an individual living thing that carries on the activities of life by means of organs which have separate functions but are dependent on each other : a living person, plant, or animal
organismic adjective

Medical Definition

organism

noun
or·​gan·​ism ˈȯr-gə-ˌniz-əm How to pronounce organism (audio)
: an individual constituted to carry on the activities of life by means of organs separate in function but mutually dependent : a living being
organismic adjective
also organismal
organismically adverb

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