Eton chap shambles along Whitehall, a sad reminder (8)
I believe the answer is:
cenotaph
'along whitehall a sad reminder' is the definition.
I can't tell whether this definition defines the answer.
'eton chap shambles' is the wordplay.
'shambles' is an anagram indicator.
'eton'+'chap'='etonchap'
'etonchap' with letters rearranged gives 'CENOTAPH'.
Can you help me to learn more?
(Other definitions for cenotaph that I've seen before include "Monument to those killed in war" , "Whitehall memorial" , "Monument built to honour soldiers who died in war" , "Monument to the war dead" , "Monument honouring the fallen" .)