The Chinese word 肥胖 is a compound word formed by combining two characters with closely related meanings to emphasize and specify the concept of obesity. The first character, 肥 (féi), primarily means "fat" or "obese", often describing excess fat or richness. The second character, 胖 (pàng), also means "fat", "plump", or "overweight", typically focusing on a person's bodily stoutness. When paired, they create a synonym compound, where each component reinforces and narrows the meaning, resulting in a formal and clinical term for the medical condition or state of being significantly overweight. This structure is common in Chinese for creating precise, nuanced vocabulary.