The term 'Extraordinary BRILLIANCE' can be summarized by the crossword solution 'ECLAT' (5 letters). ECLAT is a French word meaning 'BRILLIANCE' or 'SPLENDOR'. It is often used to describe a person's extraordinary BRILLIANCE, such as their exceptional talent or skill. It can also be used to describe a moment of great success or achievement. In other words, it is a term that is used to describe something that is truly remarkable and stands out from the rest.