Estio translates to "summer" or "summertime." While verão is the more common word for summer in Portuguese, estio is a more poetic and less frequently used term, often found in literature or more artistic contexts.
In Caetano Veloso's song, "Tempo de Estio" literally means "Summertime." The use of estio evokes a sense of classic Brazilian summer, full of warmth, light, and the vibrant energy of Rio, making it a unique and evocative choice for the song's title and lyrics.