Definitions

1. noun

a hat, especially a fashionable or formal one

“She wore a beautiful chapeau to the royal wedding.”

2. noun

a hat or other headgear worn as a symbol of office or dignity

“The king wore a chapeau as a symbol of his power.”

3. noun

a hat or other headgear, especially one worn as a disguise

“The thief wore a chapeau to hide his face.”