mononym Share definition Flag A mononym is one name that is taken from a full name or nickname. Brazilian and Portuguese futbolers often take mononyms to avoid their long names. Madonna, Bono, Ronaldo, Robinho, Ronaldinho, and Kaka are all mononyms. mononym by GabeW December 9, 2008 0 0 Get merch Get the mononym mug. Buy Now — $32.95 See more merch