symbiosis Definition

symbiosis
noun symbioses

1. biol.
A close association between two organisms of different species, usually to the benefit of both partners, and often essential for mutual survival. Compare mutualism.
2. psychol.
A mutually beneficial relationship between two people who are dependent on each other.

Derivative: symbiotic
adj

Relating to or involving symbiosis.

Etymology: 19c in these senses; 17c, meaning ‘living together': from Greek syn together + bios life.