The word 腹部 is formed by combining the character 腹 (fù), which means "abdomen" or "belly", with the character 部 (bù), which means "part" or "section". Together, they create a compound noun where the first character specifies the core concept (the abdominal area) and the second character acts as a general categorizer, refining the meaning to "the abdominal part" or "the section that is the abdomen", thus precisely pointing to that specific region of the body.