The term 'Castile Neighbor' refers to the four regions that border the autonomous community of Castile and León in Spain. The crossword solutions for this term are LEON (4 letters), GATO (4 letters), SOAP (4 letters), AVILA (5 letters), and ARAGON (6 letters). LEON is a province in Castile and León, GATO is a municipality in the province of Ávila, SOAP is a municipality in the province of Salamanca, AVILA is a province in Castile and León, and ARAGON is an autonomous community in northeastern Spain.