What is "selardi"

Selardi (Sielardi) is a lunar goddess of Urartu. She is counterpart to the Babylonian moon god, Sin. Nicholas Adontz theorizes that "Sielardi" name is derived from "Siela," meaning "woman" or "Sister," and "Ardi" which means sun. He states that in the ancient east, the moon had been considered the sister of the sun, rather than his consort.