symbiosis (n.) Look up symbiosis at Dictionary.com
1877, as a biological term, "mutually beneficial association of two different organisms," from Modern Latin, from Greek symbiosis "a living together," from symbioun "live together," from symbios "(one) living together (with another), partner," from syn- "together" (see syn-) + bios "life" (see bio-). Given a wider (non-biological) sense by 1921. An earlier sense of "communal or social life" is found in 1620s.