Green’s Dictionary of Slang

1. to infect with venereal disease; thus spiced adj. [play on SE, presumably the spice would be hot adj. (6a)].

a.1661		‘The Rebells Reign’ in Rump Poems and Songs (1662) i 315: Men were never so spic’d with the Sceptre of Christ / In the hands of a Saint in grain. / ’Twas brewed in their Hives by Citizens wives, / Who ventured their husbands far, / With Robin the fool, there was ne’re such a tool / To lead in the womens War.
1683		R. Dixon Canidia ii 49: What think ye of those dainty Dames, / That patch and paint, to kindle Flames? / By open Harlotry t’entice ye, / Clap ye, Pox ye, and Spice ye.

2. to adulterate [ext. of SE].

1798

J. Middleton View Agric. M’sex 302: The chimney-sweepers who sell soot in London, mix with it ashes and earth, sifted very small and fine: this they term Spicing the soot .