/ ˌserəˈtəʊnɪn; NAmE -ˈtoʊn-/ noun
[ U ] a chemical in the brain that affects how messages are sent from the brain to the body, and also affects how a person feels
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WORD ORIGIN
1940s: from serum + tonic + -in .
/ ˌserəˈtəʊnɪn; NAmE -ˈtoʊn-/ noun
[ U ] a chemical in the brain that affects how messages are sent from the brain to the body, and also affects how a person feels
••
WORD ORIGIN
1940s: from serum + tonic + -in .
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005