a knife in the back

a knife in the back

A grievous or supreme act of treachery or betrayal. (Usually preceding "of/for (someone).") This revelation regarding the governor's longstanding misappropriation of public funds is sure to be a knife in the back of his constituency, as well as every taxpayer in the state.
See also: back, knife
Farlex Dictionary of Idioms.
See also:
  • a stab in the back
  • stab in the back
  • stab in the back, a
  • be/come under fire
  • come under fire
  • (well,) I'll be hanged!
  • (well,) I'll be!
  • I'll be hanged
  • I'll be!
  • I'll be damned