Leaves from livery stable with O'Ferrall's novel headgear (6)
I believe the answer is:
trilby
'headgear' is the definition.
(trilby is a kind of headgear)
'leaves from livery stable with o'ferrall's novel' is the wordplay.
I cannot quite understand how this works, but
'from' could be 'by' and 'by' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for trilby that I've seen before include "du Maurier's heroine" , "Sinatra's hat?" , "Book by George du Maurier - hat" , "one mesmerised" , "Soft hat with indented crown" .)