The antonyms of the word "unamazing" are a plethora. Some of the common opposites include; astonishing, remarkable, extraordinary, astounding, exceptional, outstanding, incredible, splendid, phenomenal, and breathtaking, among others. Each of these words describes an incredible, outstanding or exceptional event or thing, which opposite from unamazing. Using such words in a sentence can create a vivid image and excitement in the mind of the reader or listener. For instance, the view from the mountain top was a breathtaking experience. Conversely, one can use unamazing's opposite to criticize situations or things that do not meet the expected threshold of greatness.