The term "up par" has different synonyms, including excellent, outstanding, remarkable, or superior. In contrast, the antonyms, or words that are opposite in meaning to "up par," are inadequate, poor, inferior, substandard, or mediocre. These words describe something that is unsatisfactory or below the expected level of quality. When a product, performance, or service fails to meet the required standards, it is considered to be below par. Thus, the opposite of up par is down par or below par. It is essential to know the antonyms of words like up par to avoid confusion and to express ideas more precisely.