This is the 457th most frequent Spanish word.
santiago
"Santiago" is a Spanish proper noun, often used as a first name or to refer to Saint James, a patron saint of Spain.
In this sentence, 'Santiago' refers to the proper name of a person, the speaker's friend.
Mi mejor amigo, Santiago, vendrá a visitarme mañana.
My best friend, Santiago, will come to visit me tomorrow.
Here, 'Santiago' is used as the name of a city, specifically the capital of Chile.
Santiago es una ciudad hermosa en Chile.
Santiago is a beautiful city in Chile.
Here, 'Santiago' is part of the phrase 'Camino de Santiago,' a specific pilgrimage route in Spain.