An inclination to defend team suffering decline (9)
I believe the answer is:
abatement
'decline' is the definition.
(thesaurus)
'an inclination to defend team suffering' is the wordplay.
'an' becomes 'a'.
'inclination' becomes 'bent' (bent is a kind of inclination).
'to defend' means one lot of letters goes inside another.
'suffering' is an anagram indicator.
'team' anagrammed gives 'atem'.
'bent' placed around 'atem' is 'batement'.
'a'+'batement'='ABATEMENT'
(Other definitions for abatement that I've seen before include "Lessening in intensity or amount" , "Subsidence" , "relief" , "mitigation" .)