dead as mutton

(as) dead as mutton

1. Certainly dead. Primarily heard in UK. I poked that squirrel with a stick and, yeah, it's as dead as mutton.
2. Totally defunct. Primarily heard in UK. Oh, that idea from last week's meeting is dead as mutton now that the CEO has vetoed it.
See also: dead, mutton
Farlex Dictionary of Idioms.

dead as mutton

BRITISH, OLD-FASHIONED
1. If a person or animal is as dead as mutton, they are completely dead. We saw a viper. It was 4 feet long and was as dead as mutton.
2. If something or someone is as dead as mutton, they are no longer active or popular. He advised him that radio was just about to become as dead as mutton because of the advent of television.
See also: dead, mutton
Collins COBUILD Idioms Dictionary, 3rd ed.
See also:
  • (as) dead as mutton
  • mutton
  • dead as a doornail
  • doornail
  • as dead as a doornail
  • (as) dead as a doornail
  • loaf of bread
  • herring
  • (as) dead as a herring
  • be dead in the water