Back page of The Dandy (3)
I believe the answer is:
fop
'the dandy' is the definition.
('fop' can be a synonym of 'dandy')
'back page of' is the wordplay.
'back' says the letters should be written backwards.
'page' becomes 'p'.
'p'+'of'='pof'
'pof' written backwards gives 'FOP'.
(Other definitions for fop that I've seen before include "A dandy, overdressed man" , "Man excessively concerned with fashion" , "he enjoys the finest dressing" , "Man excessively concerned with his appearance" , "Affected dandy" .)