The word 签证 (qiānzhèng), meaning "visa", is a compound noun formed by combining two meaningful characters: 签 (qiān), which means "to sign" or "to endorse", and 证 (zhèng), which means "certificate" or "document". It is a logical and common type of word formation in Chinese where two related morphemes are joined to create a new, specific term, in this case, a "signature document" or officially endorsed certificate issued by a consulate or embassy to permit entry into a country.