E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Garnish (g hard).
Entrance-money, to be spent in drink, demanded by jail-birds of new-comers. In prison slang garnish means fetters, and garnish-money is money given for the “honour” of wearing fetters. The custom became obsolete with the reform of prisons. (French, garnissage, trimming, verb garnir, to decorate or adorn.) (See Fielding’s and Smollett’s novels.)
