The antonyms for the word 'un-ablest' are 'able', 'capable', 'competent', 'skilled', and 'proficient'. These antonyms are used to denote the opposite meaning of the word 'un-ablest' which means 'not capable of doing something'. An individual who is able, capable, or proficient in a particular area or subject is said to have the necessary skills, knowledge, and expertise to perform well in that field. On the other hand, someone who is considered un-ablest is lacking in the required qualities and is unable to fulfill the given task. Therefore, by using antonyms, one can express a positive attribute instead of a negative one.