blouson

right|thumb|175px|An Austrian Bundespolizei blouson. right|thumb|175px|A modern nylon MA-1 flight jacket.

A blouson or blouse jacket is a jacket that is drawn tight at the waist, causing it to blouse out and hang over the waistband. Originating in military uniforms of the mid-20th century, versions continue to be used as part of military, paramilitary and law enforcement uniforms in many places. As a piece of civilian clothing, it is considered to be both sportswear and casual clothing.