Antonyms for "improves upon" refer to actions that lessen the quality or worsen the condition of something. Examples of antonyms for "improves upon" include degrade, decline, impair, worsen, and regress. When an individual degrades or declines the performance of something, they are not enhancing it, but rather making it worse. Impairing or deteriorating an object, on the other hand, means that it is becoming less effective or efficient. Lastly, worsening or regressing something means that it is returning to a former, negative state. Knowing these antonyms for "improves upon" can help people articulate the opposite of the term while communicating their ideas effectively.