This is the 790th most frequent French word.
russes
The French word "russes" means "Russians" in English.
The word refers to the origin or characteristic 'Russian' (adjective form) connected to the nouns 'poupées' (dolls).
Les poupées russes sont très colorées.
The Russian dolls are very colorful.
Here, 'russes' describes the athletes in terms of nationality, acting as an attributive adjective.
Les athlètes russes ont gagné plusieurs médailles.
The Russian athletes won several medals.
In this case, 'russes' modifies 'livres' (books) indicating the origin or style associated with Russia as an adjective.