chapeau

n.; pl. Chapeux [ F., fr. OF. chapel hat. See Chaplet. ] 1. A hat or covering for the head. [ 1913 Webster ]

2. (Her.) A cap of maintenance. See Maintenance. [ 1913 Webster ]

‖Chapeau bras ety>[ F. chapeau hat + bras arm ], a hat so made that it can be compressed and carried under the arm without injury. Such hats were particularly worn on dress occasions by gentlemen in the 18th century. A chapeau bras is now worn in the United States army by general and staff officers. [ 1913 Webster ]