This is the 3558th most frequent Catalan word.
muro
"Wall" (specifically a physical or structural wall).
In this sentence, 'muro' is used to refer to a physical wall, specifically one that can be painted to change its appearance.
Hem pintat el muro per donar-li un aspecte nou.
We painted the wall to give it a new look.
Here, 'muro' is metaphorically used to denote a barrier or divide that exists conceptually between two ideologies.
El muro entre les dues ideologies és difícil de superar.
The barrier between the two ideologies is difficult to overcome.
This uses 'muro' to describe a constructed, physical wall designed to enclose or protect an area, in this case around a house.