the common usage for ciao is goodbye, and less common as hello.

it does mean “servant” in the Venetian dialect origin of the word that is used in Italian.

see wikipedia article: http://en.wikipedia.org/Ciao

Ciao first appears in English in 1929 in Hemingway’s A Farewell to Arms, which is set in northeast Italy during World War I. It is likely that this is where Hemingway learned the word, for ciau in Venetian dialect means “servant, slave,” and, as a casual greeting, “I am your servant.” Ciau corresponds to standard Italian schiavo; both words come from Medieval Latin sclavus, “slave.” A similar development took place with servus, the Classical Latin word for “slave,” in southern Germany, Austria, Hungary, and Poland, where servus is used as a casual greeting like ciao. At the opposite end of the world, in Southeast Asia, one even sees words meaning “slave” or “your slave” that have developed into pronouns of the first person, again to indicate respect and humility

In Italian it’s an informal way of saying hello. In Spanish it means goodbye.

Goodbye or Hello, like Aloha.

Isn’t it Italian for goodbye?

goodby, adios, arrivaderci, sayonara, dosvedonya, aloha, adieu, etc.