When you greet a friend informally, you can use the word ciao. You might call out, "Ciao!"and wave as your brother steps off the train at the station.
While ciao, pronounced "chow," is a casual Italian salutation that can mean both "hello" and "goodbye," most English speakers understand it as well. You can say, "Ciao, Grandma!" when your favorite grandparent comes to visit, or wave goodbye to a departing neighbor and yell, "Ciao!" The word is a shortened version of the formal Italian schiavo, "your obedient servant," or literally, "I am your slave."