Response on litigation (8)
I believe the answer is:
reaction
'response' is the definition.
(I know that response can be written as reaction)
'on litigation' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'litigation' becomes 'action' (I've seen this before).
're'+'action'='REACTION'
(Other definitions for reaction that I've seen before include "Into care (anag)" , "Reflex; backlash" , "effect of drugs?" , "Creation found in response to event" , "Response to stimulus from creation" .)