Green’s Dictionary of Slang

a tippler, a drunkard.

1615		T. Overbury New and Choise Characters n.p.: A Water-Man [...] The Play-houses only keepe him sober; and as it doth many other Gallants, make him an afternoones man.
1621		R. Burton ‘Democritus to Reader’ Anatomy of Melancholy (1893) I 83: Beroaldus will have drunkards, afternoon men, and such as more than ordinarily delight in drink, to be mad.
1628		J. Earle Micro-Cosmographie No. 24: A Player: Your Innes of Court men were vndone but for him, hee is their chief guest [...] and the sole busines that makes them Afternoones men. [...] he is bound to make his friends friend drunk at his charge.
1830		Dublin Sketch Book n.p.: The good Baronet (Sir Francis Burdett) was not only a foxhunter, but a celebrated after-dinner man. It must have been a good bout indeed in which he was worsted [F&H].
1877		N&Q Ser. 5 VIII 112: Afternoones men, equivalent to after-dinner men. It was the custom, formerly, to dine in the halls of our Inns of Court about noon, and those who returned after dinner to work must have been much devoted to business, or obliged to work at unusual hours by an excess of it .
1933		‘William Juniper’ True Drunkard’s Delight.