Medical Definition of esculin
: a glucoside C15H16O9 from the inner bark of the horse chestnut (Aesculus hippocastaneum) and roots of the yellow jessamine (Gelsemium sempervirens) that absorbs ultraviolet rays
Seen and Heard
What made you want to look up esculin? Please tell us where you read or heard it (including the quote, if possible).