Plebeianism refers to a lack of refinement or sophistication, and can also refer to something that is commonplace or vulgar. Synonyms for this word include: crassness, vulgarity, boorishness, coarseness, roughness, tastelessness, uncouthness, crudeness, philistinism, and proletariatism. These words all share the common theme of being associated with a lack of culture or refinement. While they may be used to describe a person's behavior or mannerisms, they can also refer to art, language, or any other aspect of culture that is considered to lack sophistication or elegance. When looking for antonyms, one might consider words like refinement, elegance, culture, or sophistication.