This is the 7725th most frequent Spanish word.
lisboa
"Lisboa" is the Spanish name for Lisbon, the capital city of Portugal.
Here 'Lisboa' is a proper noun referring to the city.
Lisboa es la capital de Portugal.
Lisbon is the capital of Portugal.
Here 'Lisboa' is used as a destination and still as a proper noun.
Vamos a visitar Lisboa el próximo verano.
We are going to visit Lisbon next summer.
In this sentence, 'Lisboa' refers to the city's characteristic features, emphasizing its cultural aspect.