Rubbish dropped on French friend’s floor-covering (6)
I believe the answer is:
tatami
'floor-covering' is the definition.
(I've seen this before)
'rubbish dropped on french friend's' is the wordplay.
'rubbish' becomes 'tat' (low-quality items or material).
'dropped on' is a charade indicator (letters next to each other) (in a down clue, some letters go on top of others).
'french friend' becomes 'ami' (I've seen this before).
'tat'+'ami'='TATAMI'
(Other definitions for tatami that I've seen before include "Floor-covering" , "Jap. floor mat" , "Japanese rush and straw matting" , "Jap. room matting" , "Japanese straw mat; a mat, it (anag.)" .)