Chapeau
Pronunciation : Cha`peau"
Part of Speech : n.;
Etymology : [F., fr. OF. chapel hat. See Chaplet.]
Definition : 1. hat or covering for the head.
2. (Her.)
Defn: A cap of maintenance. See Maintenance. Chapeau bras ( Etym: [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.
pl. Chapeux.
Source : Webster's Unabridged Dictionary, 1913