This is the 4088th most frequent Spanish word.
espanyol
"Español" means "Spanish," referring to the language or something/someone from Spain.
In this sentence, 'español' is used as a noun referring to the Spanish language.
Hablo español todos los días.
I speak Spanish every day.
Here, 'español' functions as an adjective describing the language of the book.
Ese libro está escrito en español.
That book is written in Spanish.
In this example, 'español' is used as a noun representing the Spanish language as a subject.