Medium Shaftner Share definition Flag The size of your erection that is larger than a grade A softee but not quite the size of a full on rager. Wow it seems like i can't get rid of this medium shaftner because my pants are too tight. Medium Shaftner by sergiothinks October 22, 2010 0 0 Get merch Get the Medium Shaftner mug. Buy Now — $32.95 See more merch