endogenous Syllabification: (en·dog·e·nous)Pronunciation: /enˈdäjənəs/Definition of endogenous adjective having an internal cause or origin:the expected rate of infection is endogenous to the systemOften contrasted with exogenous. Biology growing or originating from within an organism:endogenous gene sequences chiefly Psychiatry (of a disease or symptom) not attributable to any external or environmental factor:endogenous depression confined within a group or society. Derivatives endogenously adverb endogenous in other Oxford dictionaries Definition of endogenous in the British & World English dictionary