sym·​bi·​o·​sis ˌsim-bē-ˈō-səs How to pronounce symbiosis (audio)
plural symbioses ˌsim-bē-ˈō-ˌsēz How to pronounce symbiosis (audio)
: the living together in more or less intimate association or close union of two dissimilar organisms (as in parasitism or commensalism)
especially : mutualism
: a cooperative relationship (as between two persons or groups)
the symbiosis … between the resident population and the immigrantsJohn Geipel

Did you know?

Symbiosis was adopted by the scientific community in the late 1800s, coming ultimately (via German) from the Greek symbíōsis, meaning “living together, companionship.” Of course, there are a lot of ways to live together and, accordingly, several flavors of symbiosis. When a biological symbiosis between two organisms is mutually beneficial, it is termed mutualism. For example, oxpeckers are birds so named because they “peck” ticks off of infested cattle and wild mammals, a likely satisfying arrangement for both parties, and textbook mutualism. When one organism lives off another at the other’s expense, however (as, for one icky instance, head lice do), it’s called parasitism. If only parents of elementary school students could call upon an equivalent of oxpeckers to engage in mutualistic symbiosis when the need arose, but alas.

Example Sentences

The bird lives in symbiosis with the hippopotamus. Their professional association was one of symbiosis.
Recent Examples on the Web Not a few had been burned, with the accumulating trash serving—in a bit of general-strike symbiosis—as more kindling for the fires that protesters had been setting each night. Lauren Collins, The New Yorker, 27 Mar. 2023 With governments and private foundations recently providing strong support for research and development in the area of engineering nitrogen fixation, crops that harness the power of natural symbiosis might soon become a key element of a more sustainable food production. Scientific American, 1 Dec. 2021 Their stellar track record of investigative journalism and captivating storytelling, combined with our commitment to creating premium programming, is the perfect symbiosis. K.j. Yossman, Variety, 12 Oct. 2022 This new symbiosis, of course, brings its own challenges. Robert Fenton, Forbes, 25 Jan. 2023 The league seems very pleased with that symbiosis. Barry Wilner, Chicago Tribune, 27 Apr. 2022 And the trick is symbiosis. Sarah Vitak, Scientific American, 8 Apr. 2022 But the other exciting thing here is that the whole idea of engineering bionic symbiosis, and 3-D printing these things into being, really works. Bill Andrews, Discover Magazine, 7 Nov. 2018 Dorian Fuller, who studies the origins and evolution of agriculture at University College London, says on a basic level agriculture is a form of symbiosis, where two species have coevolved a relationship in which one is promoting the growth of another to feed off of it. Brian Handwerk, Smithsonian Magazine, 17 May 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'symbiosis.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


borrowed from German Symbiose, borrowed from Greek symbíōsis "living together, companionship," from symbiō-, variant stem of symbioûn "to live with, live together" (from sym- sym- + bioûn "to live, pass one's life," derivative of bíos "life") + -sis -sis — more at quick entry 1

Note: As a term in life sciences German Symbiose was promulgated, if not introduced, by the mycologist Heinrich Anton de Bary (1831-88) in Die Erscheinung der Symbiose: Vortrag gehalten auf der Versammlung der Deutscher Naturforscher und Aertze zu Cassel (Strassburg, 1879); a portion of the lecture appeared earlier as "Ueber Symbiose" in Der Naturforscher, 11. Jahrgang, No. 43, October 26, 1878, pp. 400-04. He defines the word briefly as "the living together of differently denominated organisms" ("[das] Zusammenleben ungleichnamiger Organismen," p. 5). De Bary was probably aware of the slightly earlier synonymous term Symbiotismus, introduced by the plant pathologist Albert Bernhard Frank (1839-1900) in "Ueber die biologischen Verhältnisse des Thallen einiger Krustenflechten," Beiträge zur Biologie der Pflanzen, Band 2 (1877), p. 195.

First Known Use

1877, in the meaning defined at sense 1

Time Traveler
The first known use of symbiosis was in 1877


Dictionary Entries Near symbiosis

Cite this Entry

“Symbiosis.” Dictionary, Merriam-Webster, Accessed 8 Jun. 2023.

Kids Definition


sym·​bi·​o·​sis ˌsim-ˌbī-ˈō-səs How to pronounce symbiosis (audio)
plural symbioses -ˈō-ˌsēz How to pronounce symbiosis (audio)
: the living together in close association of two different kinds of organisms (as a fungus and an alga making up a lichen) especially when such an association is of benefit to both
: a cooperative relationship (as between two persons or groups)
symbiotic adjective
symbiotically adverb

Medical Definition


sym·​bi·​o·​sis ˌsim-ˌbī-ˈō-səs How to pronounce symbiosis (audio) -bē- How to pronounce symbiosis (audio)
plural symbioses -ˌsēz How to pronounce symbiosis (audio)
: the living together of two dissimilar organisms in more or less intimate association or close union
: the intimate living together of two dissimilar organisms in a mutually beneficial relationship
especially : mutualism

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