Not diminished (8)
I believe the answer is:
unabated
'not diminished' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for unabated that I've seen before include "Without diminution" , "with no loss of intensity" , "Not calmed or diminished, say storm" , "Continuing at full strength or intensity" , "with full force" .)