When you do something with eclat, you do it with great style or an amazing effect. A skilled magician performs all of her tricks with eclat.
Eclat is the gusto or flair with which you make an entrance at a party or sing a song at your school talent show. It's also a certain measure of success, especially the type that other people consider you to have — your skill on the soccer field might lend you a certain amount of eclat among your classmates, for example. The word eclat comes from the French éclat, which means "splinter or fragment," but also "flash of brilliance."