Muck Opossum Posted in M Best definition Muck Opossum An unattractive male of shady character found usually in a bar or at a party sexually harrassing every female. Male equivelant of a “swamp donkey”. Ew. You are a muck opossum. How satisfied are you with the definition? Looking for Muck Opossum meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 36 times.