This is the 613th most frequent Portuguese word.
cartão
Card.
In this context, 'cartão' means a card made of paper or similar material, used for messages or greetings.
Ele me deu um cartão de aniversário muito bonito.
He gave me a very beautiful birthday card.
Here, 'cartão' refers to a rectangular piece, typically made of plastic, used for bank transactions.
Eu perdi meu cartão de banco ontem.
I lost my bank card yesterday.
Here, 'cartão' refers to a card, often yellow or red, used in sports games to indicate penalties or fouls.