·noun Crude tartar; an acidulous salt from which cream of tartar is prepared. It exists in the juice of grapes, and is deposited from wines on the sides of the casks.
tartar, or lees of wine. N. and S. ...
A glossary of provincial and local words used in England by Francis Grose
The tartaric acid or lees adhering to the sides of wine-casks, particularly of port-wine; an article...
The Sailor's Word-Book