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.

Examples of symbiosis in a Sentence

The bird lives in symbiosis with the hippopotamus. Their professional association was one of symbiosis.
Recent Examples on the Web Not least, the revisionists enjoy a perverse symbiosis by weakening the international order from several directions at once. Hal Brands, Foreign Affairs, 29 Mar. 2024 There is a certain symbiosis with corporate leaders in much of Mr. Biden’s economic agenda. Jim Tankersley, New York Times, 3 Apr. 2024 The relationship between both parties continues to be one of complex symbiosis, despite noises to the contrary. Olia Valigourskaia, Fortune, 18 Mar. 2024 But the relationship between the hotel and the foundation is really one of total symbiosis. Gabby Shacknai, Forbes, 29 Feb. 2024 Although the major’s game of tennis is rarely recognized as a product of hominin evolution, the ability to strike a bouncing ball with a racket is evidence of an ancient symbiosis between human and tool. Chip Colwell, Smithsonian Magazine, 26 Feb. 2024 Juhl sees a future of symbiosis for human creativity and machine learning. Howard Homonoff, Forbes, 13 Feb. 2024 When the symbiosis is too perfect, people will wonder. Gabe Lacques, USA TODAY, 6 Feb. 2024 On top of the possible therapeutic effects, Gauss sees the treatment as offering a rare occasion to reconnect with the natural world, a brief symbiosis between human and annelid. Zoey Poll, New York Times, 16 Feb. 2024

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 23 Apr. 2024.

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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