Give out audible greeting to old lover (6)
I believe the answer is:
exhale
'give out' is the definition.
(I've seen this before)
'audible greeting to old lover' is the wordplay.
'audible' indicates a 'sounds like' (homophone) clue.
'greeting' becomes 'hail' ('hail' is a greeting).
'to' is a charade indicator (letters next to each other) (I've seen this in other clues).
'old lover' becomes 'ex' (an ex-lover).
'hail' sounds like 'hale'.
'hale' put after 'ex' is 'EXHALE'.
(Other definitions for exhale that I've seen before include "Discharge" , "expire" , "send forth wind" , "produce emissions" , "Emit breath" .)