Green’s Dictionary of Slang

money for drink, demanded of anyone wearing a new suit of clothes; thus in general use to mean a tip.

c.1698		B.E. Dict. Canting Crew n.p.: Beveridge, a Garnish-money, for any thing.
1725		New Canting Dict.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1979		J. McBride Traveller in the Glens n.p.: This is what happens when a Glens girl enters a room wearing a new hat for the first time: the young man who spots her is entitled to ‘gie her the beverage o’it’, i.e. kiss her .