matt rude Share definition Flag a person that looks 4-5 years younger then their age. also cannot eat meat. Guy 1: "That guy must me 21"Guy 2: "No he's a matt rude, cant even drive yet"Guy 1: "Oh." matt rude by gayweeddad69 December 19, 2011 0 0 Get merch Get the matt rude mug. Buy Now — $32.95 See more merch