The word classiness is often associated with elegance, sophistication and refinement. However, the antonyms of this word would mean the exact opposite of these qualities. Words that come to mind as antonyms include tackiness, crassness, rudeness, coarseness, and vulgarity. These words describe a lack of quality or style, and the lack of refinement or sophistication is evident in everything from appearance to behavior. For instance, an individual who displays a high degree of tackiness could be described as having no taste or style. Those who are rude or vulgar may be recognized for their lack of social grace or cultural background. Ultimately, the antonyms of classiness are used to describe something that is not tasteful, stylish or sophisticated.