The antonyms for the word "being suitable" include unsuitable, inappropriate, incompatible, incongruous, unsuited, unfitting, insufficient, inadequate, inappropriate, irrelevant, and unacceptable. These words describe things that do not fit or match the circumstances, requirements, or standards expected. Being unsuitable can lead to negative consequences and result in undesired outcomes. For instance, wearing inappropriate attire to a formal occasion can make one stand out awkwardly, while using an unsuitable method for solving a problem can result in poor outcome. Therefore, it is essential to be familiar with the antonyms of suitable to avoid errors and mistakes in communication, decision-making, and judgment.