Etymology

Noun

1. An ornamental plume on a helmet.
   • 1896 — Sir Arthur Conan Doyle, The Exploits of Brigadier Gerard, Chapter 4

     I had taken the panache from my shako so that it might escape notice, but even with my fine overcoat I feared that sooner or later my uniform would betray me.

2. Flamboyant, energetic style or action; dash; verve.
   • 1894 — Kate Chopin, Bayou Folk, At the 'Cadian Ball

     One old gentleman, who was in the habit of reading a Paris newspaper and knew things, chuckled gleefully to everybody that Alcée’s conduct was altogether chic, mais chic. That he had more panache than Boulanger. Well, perhaps he had.