Adjectnounative Share definition Flag An instance where a noun is bastardized and used as an adjective. An adjectnounative in action: Upon finding a kitchen full of dirty dishes, the thirsty man says "It's O.K., I'll just use the biggest, plasticest cup i can find." Adjectnounative by .Kirk. October 17, 2007 Get the Adjectnounative mug.