coup de main - noun
\ˌkü-də-ˈmaⁿ
Definition of coup de main : an attack that achieves complete surprise.

Watch: Billie Eilish performs 'Happier Than Ever' live on The Tonight Show.

| by Shahlin Graves

Billie Eilish performed the title-track off her new album 'Happier Than Ever' live on The Tonight Show Starring Jimmy Fallon, complete with a perfect headbanging second act.

Watch the performance below, as well as an interview with Fallon...