(as) dead as mutton British old-fashioned simile
No longer existing, living, or operating properly.
The cat was bitten by a big dog and as dead as mutton by the time I got to it.
My phone is as dead as mutton. I'm thinking of throwing it away.
It is no use turning it on. It is as dead as mutton.
To act recklessly; to have a desire for death
Secrets cannot be revealed by the dead.
This simile dates from the late 18th century.
This phrase is used to describe something very modern or updated or something that no longer looks like what it's used to.
It has been a long time since I left my high school, and now I have to admit that it's certainly not your father's high school anymore.