Razor-sharp is an adjective that is often used to describe something that is extremely sharp or precise. Antonyms for razor-sharp might be dull, blunt, imprecise, unclear, or vague. Dull is perhaps the most direct opposite, as it suggests a lack of sharpness or cutting ability. Blunt is similar, but might also imply a degree of roughness or ineffectiveness. Imprecise and unclear both suggest a lack of clarity or accuracy, while vague implies a lack of specificity or definition. While razor-sharp connotes impressive precision or sharpness, its antonyms suggest a range of less desirable qualities.