Green’s Dictionary of Slang

a face covered in boils and pimples.

c.1698		B.E. Dict. Canting Crew.
1776		Northampton Mercury 23 Sept. 3/3: Deserted from [...] the 14th Regiment of Foot [...] James Biddel [...] swarthy Complexion, lank black hair, Carbuncle-faced.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1851		Green Mountain Freeman (Montpelier, VT) 28 Aug. 2/7: Bringing the paper near his carbuncle face and straining those ‘visual organs’.
1865		Dundee Courier 14 Aug. 4/3: A drunken, mahogany-faced, carbuncle-nosed blacklsmith.