This is the 14043rd most frequent Spanish word.
sólidas
Solid.
Here, 'sólidas' describes the physical sturdiness and reliability of the building's structures.
Las estructuras del edificio son sólidas.
The building's structures are solid.
In this context, 'sólidas' metaphorically refers to the strong and well-founded reasoning behind an argument.
Tiene muy sólidas bases para su argumento.
He has very solid foundations for his argument.
Here, 'sólidas' characterizes the dependable and enduring nature of her relationships.