Harder than a cat's head

Meaning

A measure of extreme stubbornness or physical density. It is often used to describe a person who refuses to change their mind despite overwhelming evidence to the contrary.

Sassy, judgmental, blunt

Used in a sentence

• Trying to talk sense to him is harder than a cat's head.
• That old desk is harder than a cat's head to sand down.
• Her resolve was harder than a cat's head.