The origin of this name is still today quite uncertain. The theories include: 1) This name could be of Germanic or Latin origin. The folk meaning is “dwelling place, belonging to the house”. 2) Some sources link the name to the Arabic “qaṣīda”, meaning “poem "or “to sing”. Saint Casilda of Toledo († ~1050 AD) is venerated as a saint of the Catholic Church. Her feast day is celebrated on April 9. Casilda is also a city in the province of Santa Fe, Argentina.