The venereal disease. He broke his shins against Covent Garden rails; he caught the venereal disorder.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Covent Garden Abbess * Covent Garden NunNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes