• SYMBIOTIC (adjective). The adjective SYMBIOTIC has 1 sense: 1. used of organisms (especially of different species) living together but not necessarily in a relation beneficial to each. Familiarity information: SYMBIOTIC used as an adjective is very rare. SYMBIOTIC (adjective). The adjective SYMBIOTIC has 1 sense: 1. used of organisms (especially of different species) living together but not necessarily in a relation beneficial to each. Familiarity information: SYMBIOTIC used as an adjective is very rare.