ETYM New Lat., from Greek, to live together; syn with + bio life.
The relation between two different kinds of organisms that are interdependent; each gains benefits from the other.
Living together of two organisms of different kinds, especially to their mutual benefit.
Any close relationship between two organisms of different species, and one where both partners benefit from the association. A well-known example is the pollination relationship between insects and flowers, where the insects feed on nectar and carry pollen from one flower to another. This is sometimes known as mutualism.
Strictly speaking, symbiosis refers to continuous, intimate contact between mutually benefiting species, such as the fungus and alga in lichen.