The antonyms for the word "unproficient" are numerous and varied. The most common antonym for unproficient is "proficient," which means possessing skill or expertise in a particular task or subject. Other antonyms for unproficient include adept, skilled, able, accomplished, experienced, and masterful. These words imply that the person in question is proficient in their field or task and able to perform at a high level. By contrast, unproficient connotes a lack of skill or knowledge, or a difficulty in grasping new concepts. In any profession, it is important to strive for proficiency and continually develop one's skills to stay competitive and effective in the workplace.