The word 尿布 is formed by directly combining two meaningful characters: 尿 (niào), which means "urine", and 布 (bù), which means "cloth". The concept is created by simply stating the object's primary function and material, it is literally a "urine cloth". This straightforward, descriptive pairing immediately communicates the item's purpose as an absorbent fabric used for managing infant waste, resulting in the meaning "diaper".