[noun][from late 1500s] a palisade, wall, moat, natural waterway, or other structure used to divide a specific area from its surroundings, such as a castle or fort
[noun][probably from early 1600s] the area so bounded by such a structure
[noun][from 1678] a red-light district, specifically one that is divided from the rest of the town by means of a wall or fence or similar structure
[noun][from 1698](poetry, haiku) in 俳諧(haikai, “vulgar haiku”), the general realm of subject matter used for the opening line