This is the 7964th most frequent Portuguese word.
ryan
"Ryan" is not a Portuguese word; it is a common male given name of Irish origin.
In this sentence, 'a Ryan' uses the indefinite article 'um' to imply one person named Ryan out of potentially many.
Eu conheci um Ryan na festa de ontem.
I met a Ryan at yesterday's party.
Here, 'Ryan' is used as a direct address to indicate the person being spoken to.
Ryan, você pode me ajudar com a tarefa?
Ryan, can you help me with the homework?
Here, 'Ryan' serves as the proper noun identifying the subject of the sentence.