This is the 2410th most frequent Portuguese word.
alemão
"German" (referring to the language, nationality, or a person from Germany).
Here, 'alemão' is a noun referring to a male German person.
Eu conversei com um alemão ontem no evento.
I spoke with a German person yesterday at the event.
Here, 'alemão' is used as a noun referring to the German language.
O alemão é a língua oficial da Alemanha.
German is the official language of Germany.
In this sentence, 'alemão' acts as an adjective describing the nationality of the professor.