Standard Lemma guide
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
noun
A hormone, related to serotonin, that is secreted by the pineal gland, and stimulates colour change in the skin of reptiles, and is involved in the sleep and wake and reproductive cycles in mammals.
Definition source: English Wiktionary via Wiktextract
Usage: uncountable, usually
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
noun
Any material similar in its chemistry and effect to the natural hormone.
Definition source: English Wiktionary via Wiktextract
Usage: uncountable, usually
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
noun
hormone secreted by the pineal gland
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Synonyms: none provided
Antonyms: none provided
Broader terms: hormone, endocrine, internal secretion
History
From mela- + tone + -in, ultimately from Ancient Greek μέλας (mélas, “black, dark”).
Across languages
30 source translations are retained for this English entry.
