Battleground of 1945 (3,4)
I believe the answer is:
iwo jima
'battleground of 1945' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for iwo jima that I've seen before include "Japanese island" , "Largest of the Japanese Volcano Islands, heavily fortified in World War II" , "Second World War battle island" , "Jap. island (Nineteen forty five battle)" , "Pacific island (WW2 battle)" .)