Unbrilliant means not great, dull, or lacking in brilliance. Its antonyms, on the other hand, refer to something that is bright, excellent, sharp, or outstanding. The antonyms of unbrilliant include words like brilliant, dazzling, spectacular, outstanding, extraordinary, impressive, remarkable, and exceptional. These words suggest a high level of excellence, intelligence, or success, which is in contrast to unbrilliant. Using antonyms can help you to achieve greater clarity and precision in your writing, and to express yourself with greater impact and effectiveness. Whether in literature, academic writing, or everyday communication, antonyms are great tools for conveying meaning and conveying a strong sense of contrast.