Turn in battlefield data following uprising (5)
I believe the answer is:
addle
'turn' is the definition.
(thesaurus)
'in battlefield data following uprising' is the wordplay.
'in' says the answer is hidden in the clue.
'uprising' says the letters should be written backwards.
'eldda' can be found hidden inside 'battlefield data following'.
'eldda' backwards is 'ADDLE'.
(Other definitions for addle that I've seen before include "Make rotten" , "Go rotten" , "(Of egg) become rotten" , "Rot" , "(Of eggs) become rotten" .)