neurotransmitting chemical, 1948, coined from sero-, combining form of serum (q.v.) + ton(ic) + chemical suffix -in (2).
Entries linking to serotonin
serum n.
1670s, "watery animal fluid," especially the clear pale-yellow liquid which separates in coagulation of blood in wounds, etc., from Latin serum "watery fluid, whey." This is held to be from PIE *sero- "flowing, liquid," from verbal root *ser- "to run, flow" (source also of Greek oros "whey, watery parts of curdled milk;" Sanskrit sarah "flowing, liquid," sarit "brook, river"). The word was applied by 1893 to blood serum used in medical treatments.
-in 2
word-forming element in chemistry, usually indicating a neutral substance, antibiotic, vitamin, or hormone; a modification and specialized use of -ine (2).
melatonin n.
chemical formed in the pineal gland of mammals that regulates certain physiological activities, 1958, from Greek melas "black, dark" (see melano-) + ending from serotonin. So called because its secretion is inhibited by sunlight, or because it changes the skin color of certain reptiles and amphibians.