A bag fastened to the horse’s head, in which the soldiers of the cavalry put the oats given to their horses: whence the saying, I see the hose bag in his face; i.e. he has been a private man, or rode private.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
To Nose-1 * Nose GentNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes