The Chinese word 邮票 (yóupiào), meaning "postage stamp", is a compound noun formed by combining two independent characters, each contributing to its overall meaning. The first character, 邮 (yóu), relates to "mail" or "postal matters", while the second character, 票 (piào), means "ticket", "certificate", or "slip". When combined, they create a new semantic unit where 邮 specifies the category (postal system) and 票 specifies the object's form (a small, printed slip), effectively meaning "postal ticket", which accurately describes the function of a stamp as a proof of prepayment for mail service.