Noble-sounding but without issue (6)
I believe the answer is:
barren
'without issue' is the definition.
(thesaurus)
'noble-sounding' is the wordplay.
'noble' becomes 'baron' (baron is a kind of noble).
'sounding' shows a homophone (sound like).
'baron' is a homophone of 'BARREN'.
'but' is the link.
(Other definitions for barren that I've seen before include "Unable to reproduce, infertile" , "Infertile, unproductive" , "Not producing fruit" , "Dull" , "Unable to bear fruit, not fertile" .)