Story on fairy's regular helping (9)
I believe the answer is:
narration
'story' is the definition.
(I know that story can be written as narration)
'on fairy's regular helping' is the wordplay.
'regular' means one should take alternating letters.
'helping' becomes 'ration' (a ration is a serving or helping).
'on'+'fairy'='onfairy'
The alternate letters of 'onfairy' are 'nar'.
'nar'+'ration'='NARRATION'
(Other definitions for narration that I've seen before include "Voice-over in film" , "Process of storytelling" , "Story" , "Account of events" , "Spoken account" .)