Noun. A plastic bag (usually from a grocery store, bodega or other ghetto-mart) that has been inflated and borne aloft by the wind, giving it a jellyfish like appearance. Common in neighborhoods where littering is acceptable but walking on a sidewalk isn't.
I almost ran over that ho because she stepped out infront of me right as an urban jellyfish splatted up against my windshield.
by hoodrat January 04, 2005