Green’s Dictionary of Slang

1. to feign a hand-slap for the purpose of passing money and drugs between a customer and a dealer.

1975

Sepe & Telano Cop Team 56: ‘Hand jiving’ [...] is a simple, sweeping slap of hands that is universally practised by sellers and buyers of narcotics on public streets.

2. (US) to masturbate, usu. someone else.

1978

W. Brown Tragic Magic 112: With all that funky hand-jivin between your legs you lucky your brains ain’t scrambled more than they are.

3. (US) to move and slap the hands in time to the rhythm of music.

1996		A. Close Official and Doubtful 289: In a far corner two women in short-sleeved blouses are handjiving to the song’s final chorus.
1999		Guardian Weekend 18 Sept. 76: An hour of hand-jiving and hair-combing later, he was still asking the same question.