This is the 12526th most frequent Portuguese word.
sérvio
"Serbian" (relating to Serbia or its people/language).
In this sentence, 'sérvio' (Serbian) is used as an adjective describing the language.
O idioma sérvio é falado predominantemente na Sérvia.
The Serbian language is predominantly spoken in Serbia.
Here, 'sérvio' is used as a noun referring to a person from Serbia.
Ele é sérvio e me contou muito sobre seu país.
He is Serbian and told me a lot about his country.
In this example, 'sérvios' (Serbian) is used as an adjective describing customs.