one-nut wonder Share definition Flag A guy that has one testicle that is undescended, or a guy that has had a nut removed due to testicular cancer. That Mike Lowell is a one-nut wonder! (and his head is huge!) one-nut wonder by Elevcode December 3, 2005 0 0 Get merch Get the one-nut wonder mug. Buy Now — $32.95 See more merch