castilian Meaning, Definition & Usage

  1. noun the Spanish language as spoken in Castile

WordNet

Cas*til"ian noun
Etymology
Sp. castellano, from Castila, NL. Castilia, Castella. Castile, which received its name from the castles erected on the frontiers as a barrier against the Moors.
Definitions
  1. An inhabitant or native of Castile, in Spain.
  2. The Spanish language as spoken in Castile.

Webster 1913