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The jamaican term for masturbating.

Comes from the action made when doing so (the back and forth action of your fist)
*watching some porn*
"i think i jus goin go back my fist now"

"Dawg, mi a go home and back mi fist"
"YUTE! You need a girl!"
by BobbySox June 19, 2009

Words related to Back my fist

beating off beat off cranking one out jacking off wanking