shak·o also shack·o 
(shăkō, shākō, shä-)
(shăkō, shākō, shä-)n. pl. shak·os or shak·oes also shack·os or shack·oes
A stiff, cylindrical military dress hat with a metal plate or badge in front, a short visor, and a plume or pompom.
[French schako, from Hungarian csákó, from csákós (süveg), pointed (cap), from csák, peak, perhaps from Middle High German zacke, tack, nail.]