Traditional pajamas consist of a jacket-and-trousers combination made of soft fabric, such as flannel;[6] The jacket element usually has a placket front and its sleeves have no cuffs.[7] For a number of reasons (increased freedom of movement, aesthetic appeal, etc.) many men opt to sleep or lounge barechested in just the pajama trousers.
In colloquial speech, these traditional pajamas are often called PJs, jim jams, or jammies;[8] while in South Asia and South Africa, they are sometimes referred to as night suits.
Some pajamas feature a drop seat (also known as a trap door or butt flap): a buttoned opening in the seat, designed to allow the wearer to conveniently use a toilet. Drop seats were very common on pajamas made before the 1950s, but today they are rather rare.