A farewell maybe said out of love (5)
I believe the answer is:
adios
'a farewell' is the definition.
(adios is a kind of farewell)
'maybe said out of love' is the wordplay.
'maybe' indicates anagramming the letters.
'out of' is an insertion indicator (some letters on the outside of others).
'love' becomes 'o' (love means zero in tennis).
'said' is an anagram of 'adis'.
'adis' placed around 'o' is 'ADIOS'.
(Other definitions for adios that I've seen before include "Goodbye, amigo" , "Goodbye (Spanish)" , "Bye-bye (amigo)" , "Adieu, arrivederci" , "Good-bye (Sp.)" .)