Thumb rating Share definition Flag Urban Dictionary's new system of rating definitions that sucks harder than a young Thaiwanese boy. The infamous "fo' shizzle my nizzle" (first definition) used to have thousands of five star ratings, but now has 20 thumbs up. Thumb rating by Peter G June 1, 2004 0 0 Get merch Get the Thumb rating mug. Buy Now — $32.95 See more merch