Green’s Dictionary of Slang

ardent n.

spirits.

1833		Ely’s Hawk & Buzzard (NY) Aug. 31 n.p.: Smoking long nines and pouring down the ardent all day.
1840		Eve. Signal (NY) 18 Jan. n.p.: There ain’t no life preserver but the ardent. Brandy and water [...] gin and sugar.
1850		Life in Boston & N.Y. (Boston, MA) 6 Apr. n.p.: Cabman Ful—r, a great lover of the ardent.
1860		R. Nicholson Rogue’s Progress (1966) 118: All spirits being contraband in prison, the profession of the ‘whistler’ (for such is the vendor of ‘ardents’ denominated) was once very profitable.
1873		J. O’Connor Wanderings of a Vagabond 15: One of the bloods of the place, having partaken too freely of the ardent, took the liberty to sleep it off in the dress-circle.
1878		press cutting in Ware (1909) 9/1: After this we all felt in such good humour that the bottle passed freely, and I fear that more than one of our number swallowed a little too much of the ardent.
1883		Orleans Co. Monitor (Barton, VT) 30 Apr. 1/5: ‘You keep “ardents” here?’ ‘Keep — what?’ ‘Ardents — ardents — spirits, you know’.
1885		Idaho Semi-Wkly World 27 Nov. 3/1: If you are determined to pour the ardent down your throat, stick to one particular kind.
1906		Dly Capital Jrnl (Salem, OR) 31 Dec. 1/1: Dealers in Ardents [...] The local option law [...] operates to the benefit [...] of the ardent liquor business.
1909		J. Ware Passing Eng. of the Victorian Era 9/2: Ardent (Soc., 1870). A shortened form of ‘ardent spirits’. From the Mexican aqua ardente, through America.