Etymology The word endorphin is derived from / meaning "within" (endogenous, / , "proceeding from within"), and morphine, from Morpheus (), the god of dreams in the Greek mythology. Thus, endorphin is a contraction of 'endo(genous) (mo)rphin' (morphin being the old spelling of morphine).
Etymology The word endorphin is derived from / meaning "within" (endogenous, /  "proceeding from within"), and morphine, from Morpheus (), the god of dreams in the Greek mythology. Thus, endorphin is a contraction of 'endo(genous) (mo)rphin' (morphin being the old spelling of morphine).