The name Cia is a girl's name meaning "of the moon". Cia and is often added to lists like Best One-of-a-Kind Names for Girls and discussed in our forums with posts like "The Makeover Baby Name Game".
From the experts:
What's Cia short for? Cynthia or most any other C-name. Stylish in its sleek Mia-Nia minimalist feel, but may remind some of the Central Intelligence Agency.