po·co·sin (pə-kō'sĭn) n.
Chiefly South Atlantic U.S. A swamp in an upland coastal region. Also called regionally dismal.
[Possibly of Virginia Algonquian origin.] In coastal Virginia, Maryland, Delaware, and the Carolinas, a swamp or marsh can be called a pocosin or a dismal, the second term illustrated in the name of the Dismal Swamp on the border of North Carolina and Virginia. The word pocosin possibly comes from Virginia Algonquian. The early settlers used pocosin as a designation for low swampy ground, especially a wooded swamp.