Origin

The character 唇 combines two parts: the mouth radical 口 at the bottom, which directly represents the lips as a feature of the mouth, and 辰 above it, which serves as a sound hint rather than contributing to the meaning. The 辰 component doesn't mean anything related to lips—it's there because in Chinese, the character was pronounced similarly to how 辰 was pronounced. By pairing the meaningful mouth symbol with a sound guide, the character effectively represents both what lips are and how to pronounce the word.