Sin was the Babylonian moon god. His cult practiced ritual “shabatu” days where you weren’t supposed to work, make astrological predictions, or do risky things. He was said to resemble a bull (because the moon has “horns,”). He was associated with the passage of time too, I believe.
Clearly a big inspiration for the Hebrews, what with their “shabbat” days, their depictions of Yahweh as having bull’s horns, and their reverence for “Mount Sinai.”
I actually don’t know if the god Sin and the theological term “sin” are related etymologically. The Hebrew word for sin is obviously not “sin.” I reckon sin (lowercase) came from Greek/Latin/European languages?