1. Castilian (native or inhabitant of the geographic region or former kingdom of Castile, now approximately divided into the autonomous communities of Castile and León, Castilla-La Mancha and the Community of Madrid) (usually male)

2. A color of marbleized black and white, specifically associated with certain chickens. (Chile)

3. Castilian Spanish (the dialect of the kingdom or region of Castile)

4. European Spanish, Spanish Spanish (the dialects of Spain generally, particularly as opposed to those in Latin America) (inexact)

5. Spanish (the Spanish language generally) (sometimes offensive)

6. castellano (a traditional unit of mass, equivalent to about 4.8 g)

7. castellano (a former Spanish coin, notionally equivalent to a castellano of gold)

8. castellan (the lord or caretaker of a castle) (chiefly historical)