Stunning contribution to flood defence? (7)
I believe the answer is:
sandbag
'flood defence?' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for sandbag that I've seen before include "Defence against flooding" , "It's used as a bulwark against flood" , "defensive article" , "Item used in building flood defences" , "Flood barrier builder" .)