This is the 9863rd most frequent Spanish word.
belgas
Belgians.
Here, 'belgas' is used as a noun to refer to people from Belgium.
Los belgas son conocidos por su chocolate.
The Belgians are known for their chocolate.
In this context, 'belgas' functions as an adjective describing friends from Belgium.
Tengo unos amigos belgas que visitaron la ciudad el verano pasado.
I have some Belgian friends who visited the city last summer.
In this sentence, 'belgas' acts as an adjective modifying 'cervezas' (beers) to indicate their origin from Belgium.