1620s, "of or pertaining to a territory," from Late Latin territorialis, from territorium (see territory). In reference to British regiments, from 1881. In reference to an area defended by an animal, from 1920. Territorial waters is from 1841. Territorial army "British home defense" is from 1908. Territorial imperative "animal need to claim and defend territory" is from 1966.
updated on January 20, 2014