The French left a confused flier (7)
I believe the answer is:
leaflet
'flier' is the definition.
(thesaurus)
'the french left a confused' is the wordplay.
'the french' becomes 'le'.
'confused' is an anagram indicator.
'left'+'a'='lefta'
'lefta' with letters rearranged gives 'aflet'.
'le'+'aflet'='LEAFLET'
(Other definitions for leaflet that I've seen before include "Single printed sheet" , "Handbill, flyer" , "Publication on single sheet" , "little advertising!" , "It may advertise" .)