ter-ri-to-ry n, pl. -ries. 1. An area of land; region. 2. The land and waters under the jurisdiction of a state, nation, or sovereign. 3. Territory. a. A part of the United States that is not admitted as a state, that is administered by a govenor, and that has its own legislature. b. A semi-autonomous geographic region, as a colonial possession, that is dependant on an external government. 4. The area for which a person is responsable as representative or agent: a salesmean's territory. 5. Sports. The area of a field defended by a team. 6. Biol. An area inhabitated by an individual animal or a mating pair or group of animals, often defended vigorously against intruders. 7. A sphere of action or interest; province. [ME < Lat. territorium < terra, land.]