Ruined coat? Need a little yarn? (8)
I believe the answer is:
anecdote
'yarn?' is the definition.
(I've seen this in another clue)
'ruined coat? need a little' is the wordplay.
'ruined' indicates an anagram.
'little' means to remove the last letter (the word is not quite complete).
'coat'+'need'+'a'='coatneeda'
'coatneeda' with its last letter taken away is 'coatneed'.
'coatneed' is an anagram of 'ANECDOTE'.
(Other definitions for anecdote that I've seen before include "Short accoung of an incident" , "Short account of an incident" , "One acted (anag) - amusing reminiscence" , "Reminiscence, story" , "Short narration" .)