The phrase "most super excellent" is defined as the highest level of greatness or excellence. Antonyms for this phrase would include words such as mediocre, average, or subpar. These words imply a lack of quality or greatness and are the opposite of "most super excellent." Other antonyms could include words like terrible or awful, which suggest something is exceptionally bad or unpleasant. Conversely, the phrase "most super excellent" could be replaced with words such as outstanding, phenomenal, or remarkable, which convey a similar sense of awe and wonder.