Greeting at a luau (5)
I believe the answer is:
aloha
'greeting at a luau' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for aloha that I've seen before include "Hawaiian "ciao"" , "A Polynesian hello or goodbye" , "Hawaiian greeting" , "Hawaiian farewell" , "Hawaiian hello or goodbye" .)