The cap on? Whipped off, perhaps, here (8)
I believe the answer is:
cenotaph
'perhaps here' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'the cap on? whipped' is the wordplay.
'whipped' indicates an anagram.
'the'+'cap'+'on'='thecapon'
'thecapon' with letters rearranged gives 'CENOTAPH'.
'off' acts as a link.
Can you help me to learn more?
(Other definitions for cenotaph that I've seen before include "Monument honouring persons buried elsewhere" , "Feature of Whitehall" , "Tomb-like monument to people buried elsewhere" , "Monument to those killed in war" , "construction in Whitehall" .)