Eat fairly badly in story (5,4)
I believe the answer is:
fairy tale
'story' is the definition.
(thesaurus)
'eat fairly badly' is the wordplay.
'badly' indicates an anagram.
'eat'+'fairly'='eatfairly'
'eatfairly' is an anagram of 'FAIRY TALE'.
'in' acts as a link.
(Other definitions for fairy tale that I've seen before include "Children's story with magical beings" , "Children's magic tale or incredible story for adult" , "'Once upon a time...'" , "''... of New York'' (The Pogues)" , "A magical story for children" .)