Patch one damaged memorial (8)
I believe the answer is:
cenotaph
'memorial' is the definition.
(cenotaph is a kind of memorial)
'patch one damaged' is the wordplay.
'damaged' indicates anagramming the letters.
'patch'+'one'='patchone'
'patchone' with letters rearranged gives 'CENOTAPH'.
(Other definitions for cenotaph that I've seen before include "construction in Whitehall" , "Monument to people whose remains are interred elsewhere" , "Whitehall memorial" , "Empty tomb" , "Monument to the war dead" .)