Rusticalness is an uncommon word that describes something that is simple, unsophisticated, and rural in nature. Its antonym would be something that is refined, sophisticated, and urban or metropolitan in character. Some possible antonyms for rusticalness include elegance, sophistication, refinement, urbanity, metropolitanism, cosmopolitanism, and modernity. These words suggest a more polished and cultured way of living, and are often associated with cities, high culture, and modern technology. Rusticalness, on the other hand, emphasizes the simpler, more rustic aspects of life, such as natural surroundings, traditional crafts, and a slower pace of life.