mel‧a‧to‧nin /ˌmeləˈtəʊnən, ˌmeləˈtəʊnɪn $ -ˈtoʊ-/
noun [uncountable][
Date: 1900-2000;
Language: Greek;
Origin: melas 'black' + English serotonin]
a
hormone that is sometimes used as a drug to help you sleep
[TahlilGaran] Dictionary of Contemporary English ▲