The word "most acuminous" refers to someone or something that is exceptionally sharp or keen. Its antonyms would be words that describe the opposite, such as dull, blunt, or dim-witted. Other antonyms for acuminous could be obtuse, stupid, or oblivious. While being acuminous implies intelligence and perceptiveness, its antonyms convey a lack of these qualities. For example, a person who is acuminous would be quick-witted and able to make astute observations, while a person who is dull would be slow to understand and unobservant. Therefore, the antonyms for "most acuminous" describe a range of characteristics that are the polar opposite of being sharp or keen.