False rumour or story (6)
I believe the answer is:
canard
I believe this is a double definition.
'false rumour' is the first definition.
(I've seen this before)
'story' is the second definition.
(I have seen 'Untrue story' mean 'canard' so perhaps 'story' could also mean 'canard')
(Other definitions for canard that I've seen before include "False rumour also from France" , "Unfounded rumour or story" , "A false rumour from France? (6)" , "Ugly rumour" , "Baseless rumour" .)