As they say, end of story! (4)
I believe the answer is:
tale
'story' is the definition.
(I know that story can be written as tale)
'as they say end' is the wordplay.
'as they say' indicates a 'sounds like' (homophone) clue.
'end' becomes 'tail' (tail is a kind of end).
'tail' sounds like 'TALE'.
'of' acts as a link.
(Other definitions for tale that I've seen before include "Fable" , "'Story, narrative (4)'" , "An account of incidents or events" , "See 12" , "Report" .)