(as) deaf as a post informal
This idiom is likely offensive to others.
Her grandfather's as deaf as a post.
My grandma can't hear you even if you shout; she's deaf as a post.
After years of listening to very loud music, now Linda is deaf as a post.
To act recklessly; to have a desire for death
Secrets cannot be revealed by the dead.
Completely lifeless or defunct.
"(as) deaf as a post" is also "deaf as an adder". The first idiom has its origin in John Palsgrave's Acolastus (1540).
Completely dark, without any light or color
I'm scared of the basement! It's as black as a skillet!