Good-bye (5)
'good-bye' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for farewell that I've seen before include "symphony" , "Valedictory word" , "It may be said when 15" , "Cape at the southernmost point of Greenland" , "Archaic goodbye or leave-taking" .)
'good-bye' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for adieu that I've seen before include "Parting greeting" , "Leave" , "Auf wiedersehen" , "Parting word" , "Goodbye in France" .)