Green’s Dictionary of Slang

1. a brimming glass.

1688		T. Shadwell Squire of Alsatia II ii: There’s a facer for you [Drinks the glass clear off, and puts it to his face].
c.1698		B.E. Dict. Canting Crew n.p.: Facer, a Bumper without Lip-room.
1725		New Canting Dict. [as cit. c.1698].
1731		C. Coffey Devil to Pay III iii: Let every Bumper be a Facer.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
c.1750–1882		B.M. Carew Life and Adventures.
1872		J. O’Keeffe Positive Man in Works (1798) 431: Oh, Matter Thomas, shan’t we take a facer in the evening at the Blue Anchor?
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
c.1790		‘Larry’s Stiff’ Luke Caffrey’s Gost 7: If he hadn’t a make, his neck-cloth he’d pop for a facer.
1809		G. Andrewes Dict. Sl. and Cant.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1835		G. Kent Modern Flash Dict.
1848		Flash Dict. in Sinks of London Laid Open.
c.1850		Duncombe New and Improved Flash Dict.
1859		Matsell Vocabulum.
1864, 1867, 1870		Hotten Sl. Dict.
1873		Sl. Dict.

2. a glass that holds a single dram of spirits.

1864, 1867, 1870		Hotten Sl. Dict. 156: Facer [...] In Ireland, a dram.
1882		Sydney Sl. Dict. (2 edn) 4: Facer - In Ireland, a dram.

3. a glass of whisky punch.

1865		Leaves from Diary of Celebrated Burglar 28/1: After another ‘facer’ we each took a bottle to use on the way, and started for the steamer.
1873		Sl. Dict. 156: Facer [...] whisky-punch. Possibly from the suffusion of blood to the face caused by it.