This is the 12375th most frequent Spanish word.
luso
"Luso" refers to something or someone related to Portugal or Portuguese culture.
In this sentence, 'luso' is a concise adjective used to denote Portuguese origin.
El jugador luso marcó el gol decisivo en el partido.
The Portuguese player scored the decisive goal in the match.
Here, 'lusa' describes the culture as pertaining to Portugal.
La cultura lusa está llena de tradiciones y rica historia.
The Portuguese culture is full of traditions and rich history.
In this case, 'lusas' is used as an adjective agreeing in gender and plural form with 'amigas'.