SYMBIOSIS

symbiosis, mutualism

(noun) the relation between two different species of organisms that are interdependent; each gains benefits from the other

Source: WordNet® 3.1

Etymology

Noun

symbiosis (plural symbioses)

A relationship of mutual benefit, especially among different species.

(ecology) A close, prolonged association between two or more organisms of different species that normally benefits both members. An interspecies cooperation.

(biology) A close, prolonged association between two or more organisms of different species, regardless of benefit to the members.

(possibly obsolete) The state of people living together in a community.

Source: Wiktionary

Sym`bi*o"sis, n. [NL., fr. Gr. a living together, to live together; with + to live.] (Biol.)

Definition: The living together in more or less imitative association or even close union of two dissimilar organisms. In a broad sense the term includes parasitism, or antagonistic, or antipathetic, symbiosis, in which the association is disadvantageous or destructive to one of the organisms, but ordinarily it is used of cases where the association is advantageous, or often necessary, to one or both, and not harmful to either. When there is bodily union (in extreme cases so close that the two form practically a single body, as in the union of algæ and fungi to form lichens, and in the inclusion of algæ in radiolarians) it is called conjunctive symbiosis; if there is no actual union of the organisms (as in the association of ants with myrmecophytes), disjunctive symbiosis.

Source: Webster’s Unabridged Dictionary 1913 Edition