Determined action - sue for reconstruction (9)
I believe the answer is:
tenacious
'determined' is the definition.
(thesaurus)
'action sue for reconstruction' is the wordplay.
'for reconstruction' indicates an anagram (I've seen this in other clues).
'action'+'sue'='actionsue'
'actionsue' is an anagram of 'TENACIOUS'.
(Other definitions for tenacious that I've seen before include "Holding or sticking firmly" , "refusing to give up" , "Dogged" , "Persistent in holding on" , "Determined" .)