One for the Thumb Share definition Flag The fifth person on one's list of sexual partners. 1: Hey dude what happened to you last night?2: Oh dude, I got one for the thumb.1: Awesome, bro! One for the Thumb by Pittsburghlady September 19, 2011 0 0 Get merch Get the One for the Thumb mug. Buy Now — $32.95 See more merch
