A diaper or a nappy is a type of underwear that allows the wearer to urinate or defecate without the use of a toilet, by absorbing or containing waste products to prevent soiling of outer clothing or the external environment. When diapers become wet or soiled, they require changing, generally by a second person such as a parent or caregiver. Failure to change a diaper on a sufficiently regular basis can result in skin problems around the area covered by the diaper.
Diapers are primarily worn by infants, toddlers who are not yet potty trained, and by children who experience bedwetting. They are also used by adults with incontinence, in certain circumstances where access to a toilet is unavailable, or as part of a sexual fetish. These can include those of advanced age, patients bed-bound in a hospital, individuals with certain types of physical or mental disability, and people working in extreme conditions, such as astronauts. It is not uncommon for people to wear diapers under dry suits.
The Middle English word diaper originally referred to a type of cloth rather than the use thereof; “diaper” was the term for a pattern of repeated, rhombic shapes, and later came to describe white cotton or linen fabric with this pattern. According to the Oxford Dictionary, it is a piece of soft cloth or other thick material that is folded around a baby’s bottom and between its legs to absorb and hold its body waste.
The first cloth diapers consisted of a specific type of soft tissue sheet, cut into geometric shapes. This type of pattern was called diapering and eventually gave its name to the cloth used to make diapers and then to the diaper itself, which was traced back to 1590s England. This usage stuck in the United States and Canada following the British colonization of North America, but in the United Kingdom the word “nappy” took its place. Most sources believe nappy is a diminutive form of the word napkin, which itself was originally a diminutive.