Definify.com
Webster 1913 Edition
Mantelet
1. 
(a) 
A short cloak formerly worn by knights. 
(b) 
A short cloak or mantle worn by women. 
A 
mantelet 
upon his shoulders hanging. Chaucer.
2. 
(Fort.) 
A musket-proof shield of rope, wood, or metal, which is sometimes used for the protection of sappers or riflemen while attacking a fortress, or of gunners at embrasures; – now commonly written 
mantlet
.