Poet in denial reviewing retrospective (8)
I believe the answer is:
verlaine
'poet' is the definition.
(Paul Verlaine 1844-1896)
'in denial reviewing retrospective' is the wordplay.
'in' says the answer is hidden in the clue.
'retrospective' shows that the letters should be reversed in order.
'enialrev' is hidden within 'denial reviewing'.
'enialrev' reversed gives 'VERLAINE'.
(Other definitions for verlaine that I've seen before include "Paul -, nineteenth-C French poet" , "Paul --, nineteenth century French poet" .)