This is the 2466th most frequent Spanish word.
vasco
Basque (related to the Basque people, language, or region in northern Spain and southwestern France).
In this sentence, 'vasco' is used as an adjective to describe the language originating from the Basque region.
El idioma vasco es una lengua muy antigua.
The Basque language is a very old tongue.
Here, 'vasco' acts as a noun referring to a person from the Basque region.
Mi abuelo era un orgulloso vasco que vivía en Bilbao.
My grandfather was a proud Basque man who lived in Bilbao.
In this third sentence, 'vasco' is used as an adjective to qualify the type of cake, indicating it is typical of the Basque culinary tradition.