[ sim-bee-oh-sis, -bahy- ]
/ ˌsɪm biˈoʊ sɪs, -baɪ- /
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noun, plural sym·bi·o·ses [sim-bee-oh-seez, -bahy-]. /ˌsɪm biˈoʊ siz, -baɪ-/.

  1. the living together of two dissimilar organisms, as in mutualism, commensalism, amensalism, or parasitism.
  2. (formerly) mutualism (def. 1).
Psychiatry. a relationship between two people in which each person is dependent upon and receives reinforcement, whether beneficial or detrimental, from the other.
Psychoanalysis. the relationship between an infant and its mother in which the infant is dependent on the mother both physically and emotionally.
any interdependent or mutually beneficial relationship between two persons, groups, etc.



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Origin of symbiosis

1615–25; <Greek symbíōsis, equivalent to sym-sym- + biō (variant stem of bioûn to live) + -sis-sis


sym·bi·ot·ic [sim-bee-ot-ik, -bahy-], /ˌsɪm biˈɒt ɪk, -baɪ-/, sym·bi·ot·i·cal, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

How to use symbiosis in a sentence

British Dictionary definitions for symbiosis

/ (ˌsɪmbɪˈəʊsɪs, ˌsɪmbaɪˈəʊsɪs) /


a close and usually obligatory association of two organisms of different species that live together, often to their mutual benefit
a similar relationship between interdependent persons or groups

Derived forms of symbiosis

symbiotic or rare symbiotical, adjective

Word Origin for symbiosis

C19: via New Latin from Greek: a living together; see symbiont
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for symbiosis

[ sĭm′bē-ōsĭs, -bī- ]

n. pl. sym•bi•o•ses (-sēz)

A close, prolonged association between two or more different organisms of different species that may, but does not necessarily, benefit each member.
A relationship of mutual benefit or dependence.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for symbiosis

[ sĭm′bē-ōsĭs ]

The close association between two or more organisms of different species, often but not necessarily benefiting each member. The association of algae and fungi in lichens and of bacteria living in the intestines or on the skin of animals are forms of symbiosis. Some scientists believe that many multicellular organisms evolved from symbiotic relationships between unicellular ones and that the DNA-containing organelles within certain eukaryotic cells (such as mitochondria and chloroplasts) are the product of symbiotic relationships in which the participants became interdependent. There are four forms of symbiosis: amensalism, commensalism, mutualism, and parasitism.

Other words from symbiosis

symbiotic adjective
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for symbiosis

[ (sim-bee-oh-sis, sim-beye-oh-sis) ]

The process by which two organisms live together, usually to their mutual benefit. An example of a symbiotic pair are cows and the bacteria that live in their digestive tracts, enabling them to digest cellulose in grass.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.