A person extremely jealous of his wife, is said to be horn mad. Also a cuckold, who does not cut or breed his horns easily.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
See also the definition in Nathan Bailey's 1736 dictionary of canting and thieving slang.
Horn Fair * Horn WorkNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes