签字,是在文书、契约上的署名,表示承诺应许,以为个人私证,后来称为“画押”或“押字”。三国时期,魏嘉平六年(254),优人云午等人为了促成魏齐王曹芳杀掉司马师,大唱“青头鸡”。青头鸡就是鸭,因鸭头多青色;“鸭”与“押”同音,故云午等人大唱“青头鸡”,暗示曹芳在处决司马师的诏书上签字的意思。从此就有了“押字”之称。 Signature, is signed in the instrument, the contract, promised promised, that a personal certificate, and later known as “detention” or “charge word.” Three Kingdoms period, Weijia Ping six years (254), excellent people noon et al. In order to help Wei Qi Wang Cao Fang kill Sima division, singing “green head chicken.” Green-headed chickens are ducks, because ducks are more cyan; “duck” and “detention” are homophones, so noon et al sing “green-headed chickens”, suggesting that Cao Fang signed the edict of Sima Shi on the meaning. From then on there is “the word” said.