hand jig, n. — Green’s Dictionary of Slang

hand jig n.

also three-fingered hand jig

[SE hand + jig, a fidgety movement]

(US prison) masturbation, usu. of one prisoner by another.

1962–68		in B. Jackson In the Life (1972) 421: They just give hand-jigs or they’ll give blowjobs....They’ll...give each other hand-jigs.
1971–2		C. Shafer ‘Catheads [...] and Cho-Cho Sticks’ in Abernethy Bounty of Texas (1990) 206: handjig, n. – masturbation. [Ibid.] 216: three-fingered handjig, n. – three fingered masturbation.