The term 'Military Chapeau' refers to a type of headgear worn by military personnel. The most common type of this headgear is the KEPI, which is a four-letter word that can be found in crossword puzzles. The KEPI is a cap with a flat circular top and a visor, usually made of cloth or leather. It is typically adorned with a badge or insignia to indicate rank or unit. The KEPI is a popular choice for military personnel due to its practicality and comfort.