mugun Posted in M Best definition mugun Yoruba (Nigerian) slang for an idiot, or else a scammer. Used in 419 Advance-Fee fraud circles. That mugun wanted me to help him hide $40,000,000 from a forgotten inheritance. How satisfied are you with the definition? Looking for mugun meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 113 times.