褪黑激素 tuìhēijīsù melatonin Definitions Defs Origin Strokes Stroke Words Sentences Sents 褪 tuì nounverb to fade to lose color or luster; to fade away or disappear, such as colors, marks, or feelings黑 hēi adjective black the color of coal or ink; opposite of 白 bái激素 jīsù noun hormone hormone; a substance produced in an organism that regulates physiological activities such as metabolism and growth
