松果体素 sōngguǒtǐsù melatonin Origin Definitions Defs Strokes Stroke Words Sentences Sents 松果体 松果體 sōngguǒtǐ pineal body pineal body; the pineal gland, a small endocrine gland in the brain shaped like a pine cone素 sù noun element (bound form) essential part; element; constituent; basic nature