"Half sun and moon" is not a standard astrological or astronomical term. It's likely a phrase you've encountered in a specific context, such as a piece of art, literature, or a personal interpretation.

To understand its meaning, we need more information. Please provide:

* The source: Where did you see or hear this phrase?

* Context: What was being discussed or depicted when you encountered this phrase?

With more context, I can help you understand the meaning of "half sun and moon".