The term outhouse originally referred to an outbuilding, or any small
structure away from a main building, used for a variety of purposes,
but mainly for activities not wanted in the main house. Outhouses are
used for storage, animals, and cooking, to name a few uses. In North
American English, an outhouse (sometimes also called a backhouse) is
now a small enclosure around a pit that is used as a toilet. Other names
include the "shitter", "shithouse", "crapper",
"john."