symbiotic - n.
(pl. symbioses)
1 a an interaction between two different organisms living in close physical association, usu. to the advantage of both (cf. ANTIBIOSIS). b an instance of this.
2 a a mutually advantageous association or relationship between persons. b an instance of this.

symbiotic adj. symbiotically adv. [mod.L f. Gk sumbiosis a living together f. sumbioo live together, sumbios companion (as SYN-, bios life)]