Taishan 泰山 [Mt. Tai]

Taishan is a word dedicated to referring to a male’s father-in-law. A male’s father-in-law is also called yuezhang 岳丈, which may originate from an entry in Hanshu 漢書 [The Book of Han] that called big mountains as yueshan 岳山, while smaller mountains as yuexushan 岳婿山. While big mountains represent the head of the family that is in charge of the small mountains, so yue 岳 became the term for father-in-law while xu 婿 became the term for son-in-law. And because Mt. Tai is the head of wuyue 五岳, the five famous mountains (East Great Mountain Tai 泰, West Great Mountain Hua 華, Center Great Mountain Song 嵩, South Great Mountain Heng 衡, North Great Mountain Heng 恆), so taishan [Mt. Tai] is also used to refer to father-in-law. There is another saying claiming using the word taishan to refer to a man’s son-in-law originates from Duan Chengshi’s 段成式 (died 863) Youyang zazu 酉陽雜俎 [Miscellaneous Morsels from Youyang], which include an anecdote about Zhang Yue 張說 (667-731), who once helped the emperor on the sacrifice to Mt. Tai, covertly promoted his own son-in-law to a higher position. When the emperor noticed this malpractice and interrogated him, Zhang got nothing to reply while his colleague taunted him by saying that it must have come from the power of Mt. Tai. Since then, taishan (Mt. Tai) has been associated with father-in-law.