The crossword solution for the term 'Carnival City, for short' is Rio, which is a three-letter word. Rio de Janeiro, commonly known as Rio, is the second-most populous city in Brazil and the sixth-most populous in the Americas. It is the capital of the state of Rio de Janeiro and is known for its natural settings, Carnival celebrations, samba, Bossa Nova, and balneario beaches. Rio is also home to the famous Christ the Redeemer statue atop Corcovado mountain. The city is also known for its annual Carnival celebration, which is considered the largest carnival in the world.