5-hydroxytryptamine 5-hydroxy-3-methylglutaryl-coenzyme a reductase • 5index · · · Info · Definitions · Synonyms · Characters · · 5-hydroxytryptamine · · Text Common · · Latin · · Scripts 19 · · Length 1 · · Syllables Definitions · · · (noun) a neurotransmitter involved in e.g. sleep and depression and memory. Synonyms: serotonin. · · Noun Definition 1 Synonyms · · · serotonin · · Synonym 1 Characters · · - hyphen-minus U+002D 5 digit five U+0035 a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 h latin small letter h U+0068 i latin small letter i U+0069 m latin small letter m U+006D n latin small letter n U+006E o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072 t latin small letter t U+0074 x latin small letter x U+0078 y latin small letter y U+0079