Original: The Vespucci expedition also named the Potengi ( Tupi-Guarani for '' River of Shrimps '' ) river , whose considerably large mouth contrasted with the nearby bodies of water , '' Rio Grande '' ( Portuguese for '' Great River '' ) , after which the Captaincy , Province , and State were named .
Simplified: The Vespucci expedition also named the Potengi river , '' Rio Grande '' . The name is Portuguese for '' Great River '' .