symbiosis

UK: /ˌsɪmbaɪˈəʊsɪs/

US: /ˌsɪmbiˈoʊsɪs, -baɪ-/

US: (sim′bē ō′sis, -bī-)

Inflections of 'symbiosis' (n): npl: symbioses

WordReference Random House Learner's Dictionary of American English © 2025

sym•bi•o•sis /ˌsɪmbiˈoʊsɪs, -baɪ-/   n., pl. -ses /-siz/ .

1. Ecology [uncountable] the living together of two very different or dissimilar living things, as when one living thing is a parasite or lives off another.
2. any relationship that involves dependence between two persons, groups, etc.:
   [countable] The press and the president have an odd symbiosis: Each may despise the other and yet each depends on the other.

sym•bi•ot•ic /ˌsɪmbiˈɑtɪk/  adj. 

WordReference Random House Unabridged Dictionary of American English © 2025

sym•bi•o•sis  (sim′bē ō′sis, -bī-), n., pl. -ses (-sēz). 

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

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

sym•bi•ot•ic  (sim′bē ot′ik, -bī-) sym′bi•ot′i•cal, adj.  sym′bi•ot′i•cal•ly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

symbiosis / ˌsɪmbɪˈəʊsɪs ˌsɪmbaɪˈəʊsɪs/ noun

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

Etymology: 19th Century: via New Latin from Greek: a living together; see symbiont

ˌsymbiˈotic, ˌsymbiˈotical adjective