Used to express greeting or farewell.(interjection)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "ciao" in a sentence
"I suppose I could say "ciao" - which does have a certain etymological background of coming from the Italian schiavo, which means "I am your slave," and I don't much want to say that either..."
"Shopping is a bit weird, since I was taken from the Bing site and dumped at somewhere called ciao!"
"You smile and wave when you spot each other, yellow maps and cameras in hand; maybe you exchange "ciao" s."