Castilian is a noun and adjective that refers to the region and former kingdom of Castile in Spain; in particular, it may refer to a native person of Castile or to the language of this region, and is therefore considered by many to be a synonym of Spanish, though with different nuances. The following articles provide further information. Castile, for information on the region and its people. Castilian people, for the ethnic group from this region. Spanish language, for general information on t… (More on Castilian)