The Chinese word "大号" (dàhào) is a compound noun formed through semantic combination, where the modifier "大" (dà), meaning "big" or "large", is directly attached to the head noun "号" (hào), which in this context means "size" or "number". It functions literally to denote the largest size in a graded series (e.g., clothing). By a common metaphorical extension, it also serves as a common euphemism for "to defecate", where "号" implicitly refers to "one's business" and "大" distinguishes it from "小号" (xiǎohào), or urination. This formation exemplifies how Chinese compounds often create new, specific meanings through the logical and often culturally contextual pairing of simple, meaningful characters.