This is the 7558th most frequent Portuguese word.
ohio
"Ohio" is not a Portuguese word; it refers to a U.S. state.
In this sentence, 'Ohio' is used as a proper noun referring to the state of Ohio in the United States.
Eu planejo visitar Ohio nas próximas férias.
I plan to visit Ohio on my next vacation.
Here, 'rio' means river and does not relate to 'Ohio'. It is used to demonstrate that similar-sounding words can have different meanings.
O rio parece bem calmo hoje.
The river seems quite calm today.
Again, in this sentence 'Ohio' is referenced as the name of the state in the U.S., being emphasized in a geographical conversation.