Debonairity, meaning dapper or suave, can be described as a state of being sophisticated and polished. Its antonyms are words that signify the opposite of debonairity. One antonym is clumsy, which expresses a lack of grace and finesse. Another antonym could be unsophisticated, which implies rudeness and awkwardness. Additionally, another antonym for debonairity is unpolished, which depicts a lack of refinement and cultivation. Lastly, gauche, which refers to clumsiness and lack of tactfulness, can also be an antonym for debonairity. In summary, debonairity can be defined as refined elegance, and its antonyms are clumsy, unsophisticated, unpolished, and gauche.