Black-jack
Full definition of black-jack
Noun
black-jack
(countable and uncountable; plural black-jacks)- (obsolete, mineral, UK) Sphalerite; zincblende.
- (obsolete) Caramel or burnt sugar, used to colour wines, spirits, ground coffee, etc.
- (obsolete) A large leather vessel for beer, etc.
- (obsolete) The Quercus nigra, or barren oak.