The phrase "what amazing" seems to be a fragment and might be a typographical error. The correct form could be "what an amazing" or "how amazing," which is an expression used to convey a strong sense of admiration or astonishment about something. It emphasizes the exceptional quality or impressiveness of a person, object, event, or situation.
The word "amazing" originates from the Old English word "amazan," which means to confuse or to perplex. Over time, it evolved in the English language to mean causing great surprise or wonder. The prefix "what" serves as an intensifier, emphasizing the extent of amazement.
If you believe that "what amazing" is correct and not a typo, please let me know!