Longman Dictionary of Contemporary English homepage

Date: 1900-2000
Language: Greek
Origin: melas 'black' + English serotonin

melatonin

 noun
     
Related topics: Human, Drugs, Medicines
mel‧a‧to‧nin [uncountable]
a hormone that is sometimes used as a drug to help you sleep
Definition from the Longman Dictionary of Contemporary English
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