tiff, v.¹ — Green’s Dictionary of Slang

tiff v.¹

[? taffeta adj. or 15C SE tiff, to be busy with trifles]

(UK Und.) to have sexual intercourse.

c.1698		B.E. Dict. Canting Crew n.p.: Tiffing, c. lying with a Wench.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.