Fragment of aretalogy recedes after a while (5)
I believe the answer is:
later
'after a while' is the definition.
(I've seen this in another clue)
'fragment of aretalogy recedes' is the wordplay.
'fragment of' indicates the answer is hidden within the clue (I've seen this in other clues).
'recedes' says the letters should be written backwards (I've seen 'receding' mean this).
'retal' can be found hidden inside 'aretalogy'.
'retal' reversed gives 'LATER'.
(Other definitions for later that I've seen before include "After a given point in time" , "bye" , "after the rest?" , "Eventually" , "At a time in the future" .)