organism

noun

or·​gan·​ism ˈȯr-gə-ˌni-zəm 

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

ˌȯr-gə-ˈniz-mik 

adjective

or less commonly organismal

ˌȯr-gə-ˈniz-məl 

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

The color of the ocean is a literal reflection of what’s in it — from microscopic plant-like organisms called phytoplankton to marine debris. — Laura Paddison, CNN Money, 5 Nov. 2026

Despite their enormous size and widespread presence in complex organisms, researchers still cannot explain their biological purpose. — Aamir Khollam, Interesting Engineering, 4 Nov. 2026

The chemical is associated with oxidizing properties, acute toxicity and reproductive toxicity and is a high-level hazard to aquatic organisms. — Angela Velasquez, Footwear News, 2 Nov. 2026

The idea is that high-intensity fires such as the 2025 Eaton fire and Palisades fire often sterilize soil, killing all its beneficial organisms and fungi, and leave behind various contaminants. — Pedro Moura, Los Angeles Times, 1 Nov. 2026

Word History

First Known Use

circa 1774, in the meaning defined at sense 1

Phrases Containing organism

• genetically modified organism
• mycoplasma-like organism
• pleuropneumonia-like organism

Rhymes for organism

• autism
• fascism
• racism
• sikhism
• sophism
• statism
• sufism
• thomism
• tourism
• tropism
• abolitionism
• aldosteronism

Kids Definition

organism

noun

or·​gan·​ism ˈȯr-gə-ˌniz-əm 

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

ˌȯr-gə-ˈniz-mik 

adjective

Medical Definition

organism

noun

or·​gan·​ism ˈȯr-gə-ˌniz-əm 

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

organismic

ˌȯr-gə-ˈniz-mik 

adjective

also organismal

-məl 

organismically

-mi-k(ə-)lē 

adverb