The Collaborative International Dictionary
Esculin
Esculin \Es*cu"lin\, n. [See Esculic.] (Chem.) A glucoside obtained from the [AE]sculus hippocastanum, or horse-chestnut, and characterized by its fine blue fluorescent solutions. [Written also [ae]sculin.]
Wiktionary
esculin
n. (context organic compound English) A (l en coumarin) (l en glucoside) which exists in horse chestnut ((taxlink Aesculus hippocastanum species)), California buckeye ((taxlink Aesculus californica species)), prickly box ((taxlink Bursaria spinosa species)) and in daphnin (the dark green resin of (taxlink Daphne mezereum species)).