This is the 2882nd most frequent Spanish word.
rusas
The Spanish word "rusas" means "Russian (feminine plural)" in English.
In this sentence, 'rusas' is an adjective modifying 'matrioshkas,' indicating the origin of the dolls as Russian.
Las matrioshkas rusas son muy bonitas.
Russian matryoshkas are very beautiful.
Here, 'rusas' is part of a compound noun 'montañas rusas,' which literally translates to 'Russian mountains,' a term used to denote roller coasters, demonstrating metaphorical usage in Spanish.
Me encantan las montañas rusas porque son emocionantes.
I love roller coasters because they are thrilling.
In this instance, 'rusas' is an adjective describing 'jugadoras,' specifying their nationality as Russian.