Easy target saving crooked donor (4,4)
I believe the answer is:
barn door
'easy target' is the definition.
(I've seen this before)
'saving crooked donor' is the wordplay.
'saving' becomes 'bar' (I've seen this before).
'crooked' indicates an anagram (a crooked or disrupted version of the letters).
'donor' anagrammed gives 'ndoor'.
'bar'+'ndoor'='BARN-DOOR'
(Other definitions for barn door that I've seen before include "you can't miss it" , "Unmissable target" , "What a bad shot can't hit" , "No point in locking it after the horse has bolted" , "Easy target" .)