The word "腰围" is formed by combining the character "腰", meaning waist, which incorporates the body radical "月" for semantic meaning and "要" for phonetic indication, with the character "围", meaning to surround or enclose, which uses the enclosure radical "囗" for semantics and "韦" for phonetics. Together, they create a compound where "腰" specifies the body part and "围" denotes the action of measuring around it, resulting in the literal meaning of "waist circumference".