Castilian

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A native or inhabitant of Castile.
• noun A person of Castilian ancestry.
• noun The Spanish dialect of Castile.
• noun The standard literary and official form of Spanish, which is based on this dialect.
• adjective Of or relating to Castile or its people, language, or culture.

from The Century Dictionary.

• Pertaining to Castile (formerly written Castille), a former kingdom in the central part of Spain, now divided into the provinces of Old and New Castile.
• noun An inhabitant or a native of Castile.

from the GNU version of the Collaborative International Dictionary of English.

• noun An inhabitant or native of Castile, in Spain.
• noun The Spanish language as spoken in Castile.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• proper noun The main and official language of Spain, Peru, Colombia, Chile, Argentina, Ecuador, Mexico, etc.
• noun A native of Castile.
• adjective Of, from, or relating to Castile.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the Spanish language as spoken in Castile