E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Pot valour; the braggadocio which is the effect of having drunk too much gin. Gin is a corrupt contraction of Geneva, or, rather, of genièvre. The juniper-berry at one time used to flavour the extract of malt in the manufacture of gin. It may be used still in some qualities of gin. (See DUTCH COURAGE.)