This is the 4784th most frequent Portuguese word.
estrangeiro
"Estrangeiro" means "foreigner" or "foreign."
Here, 'estrangeiros' qualitatively describes 'países', meaning countries other than one's own.
Ele sempre teve interesse em aprender idiomas de países estrangeiros.
He has always been interested in learning languages from foreign countries.
In this sentence, 'estrangeiro' defines the noun 'país', indicating that it is a country outside of one's homeland.
Ao visitar um país estrangeiro, é importante respeitar suas culturas.
When visiting a foreign country, it is important to respect their cultures.
Here, 'estrangeiro' is used as a noun to describe a person not native to the location they are currently in.