ㄙㄨˋㄇㄟˋmèiㄆㄧㄥˊpíngㄕㄥshēng

  1. 向來不相識拍案驚奇·》:素昧平生厚意!」儒林外史·第一》:先生素昧平生何以便學生?」素昧生平」。

to have never met sb before (idiom)​; entirely unacquainted, a complete stranger, not to know sb from Adam
vollkommen unbekannt (Person)​