This is the 11505th most frequent French word.
rez
"Rez" is short for "rez-de-chaussée," meaning "ground floor" in English.
Here, "rez" is part of the term "rez-de-chaussée," which means "ground floor" — used in the context of buildings and apartments.
Je vis au rez-de-chaussée de cet immeuble.
I live on the ground floor of this building.
In this sentence, "rez" is used metaphorically to indicate a level, similar to "niveau."
Le tableau est au rez de sa créativité.
The painting is at the level of his creativity.
Here, "rez" denotes the ground or the base level, referring to the physical ground or floor.