piercin' the giblets Share definition Flag engaging in the act of pumpin' the rump, or butt fucking. Anal intercourse. Shit, gee money, that ass was tight! I spent the last hour piercin' the giblets! piercin' the giblets by Bill B. July 4, 2005 0 0 Get merch Get the piercin' the giblets mug. Buy Now — $32.95 See more merch