To kiss. I had a smack at her muns: I kissed her mouth. To smack calves skin; to kiss the book, i.e. to take an oath. The queer cuffin bid me smack calves skin, but I only bussed my thumb; the justice bid me kiss the book, but I only kissed my thumb.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Smabbled * SmacksmoothNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes