共きょう生せい生せい物ぶつMeanings1nounsymbiontA biological term for an organism living in symbiosis with another. Used in scientific contexts.サンゴと褐かっ虫ちゅう藻そうは共きょう生せい生せい物ぶつの関かん係けいにある。Coral and zooxanthellae are in a symbiotic relationship.