This is the 1886th most frequent Spanish word.
italiano
"Italiano" means "Italian" in English.
Here, "italiano" is used as an adjective describing the type or origin of the restaurant, indicating it specializes in Italian cuisine.
El restaurante italiano prepara la mejor pasta de la ciudad.
The Italian restaurant prepares the best pasta in town.
In this sentence, "italiano" is used as a noun to refer to the Italian language, a skill or subject.
Hablo italiano fluido porque estudié en Roma.
I speak Italian fluently because I studied in Rome.
"Italiano" here functions as an adjective describing the nationality of the friend, indicating he is from Italy.