Rio is a proper noun referring to a city in Brazil or to a river, or to the name of a person or a brand in some contexts. In English, it is typically pronounced with two syllables and a stress on the first: RI-o, closely resembling rye-oh; in Portuguese it’s pronounced ree-oo with a strong palatal onset. The term is widely used in travel, geography, and pop culture, and may be adopted without translation in many languages."
Full pronunciation guide
