脑内啡 nǎonèifēi endorphin Origin Definitions Defs Strokes Stroke Words Sentences Sents 脑 腦 nǎo noun brain The brain of a person or animal; the organ in the head that controls thought and movement.内 內 nèi locative heart (bound form) inside the body or mind; the internal organs; the heart; one's inner feelings or conscience啡 fēi phonetic [phonetic] (bound form) used in loanwords, such as in 咖啡 kāfēi and 吗啡 mǎfēi