[mel.a.to.nin] n [Gk melas black + -tonin (as in serotonin)] (1958): a vertebrate hormone of the pineal gland that produces lightening of the skin by causing concentration of melanin in pigment-containing cells
MELATONIN
Meaning of MELATONIN in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012