Origin

This character combines the body radical 月 (flesh or internal organs) on the left with 包 on the right, which serves as a sound hint for the pronunciation ホウ. The 月 component signals that this is about something inside the body, while 包 — which originally meant "wrap" or "bundle" — suggests the idea of something enclosed or contained. Together, the character came to mean the placenta and other sac-like structures within the body that contain and protect tissue.