Wordnet 3.0
NOUN (1)
1. 
 an acknowledgment that can be used to say hello or goodbye (aloha is Hawaiian and ciao is Italian); 
[syn: aloha, ciao]
WordNet (r) 3.0 (2006):
ciao
    n 1: an acknowledgment that can be used to say hello or goodbye
         (aloha is Hawaiian and ciao is Italian) [syn: aloha,
         ciao]