rio Rio • riot · · · Info · Definitions · Characters · · rio · · Text Latin · · Script 3 · · Length Definitions · · · (noun) the former capital and 2nd largest city of Brazil; chief Brazilian port; famous as a tourist attraction. Synonyms: Rio de Janeiro, Rio. · · Noun Definition 1 Characters · · i latin small letter i U+0069 o latin small letter o U+006F r latin small letter r U+0072