This is the 271st most frequent Portuguese word.
porto
"Porto" in Portuguese means "port" or "harbor" in English.
In this sentence, 'porto' is used to mean a harbor or docking place where ships can load and unload.
O navio chegou ao porto.
The ship arrived at the port.
Here, 'Porto' refers to the name of the Portuguese city, which is a proper noun.
Vou para o Porto no próximo fim de semana.
I am going to Porto next weekend.
In this context, 'porto' describes a specific type of wine, namely Port wine originating from Portugal.