This is the 2350th most frequent Portuguese word.
paulinho
"Paulinho" is a diminutive form of "Paulo," meaning "little Paulo" or "Paulie."
Here, 'Paulinho' is used as a proper noun, likely to refer to a person affectionately using a diminutive form of the name 'Paulo'.
O Paulinho é muito bom em futebol.
Paulinho is very good at football.
In this context, 'Paulinho' is used as a proper noun given to a dog, showing how diminutive forms can also be used for nicknames regardless of the subject's identity.
O cachorro do vizinho, o Paulinho, é muito travesso.
The neighbor's dog, Paulinho, is very naughty.
Here, 'Paulinho' is again a proper noun used in possession, indicating that the toy belongs to the person affectionately called Paulinho.