(terminate the employment of)
to cut off one's head―behead one―decapitate one
to cut off one's head―behead one―decapitate one
to cut off one's head―behead one―decapitate one―(首にするの意味なら)―dismiss one―cashier one
to cut off the head of someone or something
首を振る.
やじられる; 首になる.