Heroic tale in 'The Pickwick Papers' (4)
I believe the answer is:
epic
'heroic tale' is the definition.
(I've seen this in another clue)
'in the pickwick papers' is the wordplay.
'in' indicates a hidden word.
'EPIC' is hidden within 'the pickwick papers'.
(Other definitions for epic that I've seen before include "of impressive proportions?" , "eg Beowulf" , "Vast in scale" , "Long, heroic story" , "Heroic, huge" .)