Backless slippers (5)
I believe the answer is:
mules
'backless slippers' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for mules that I've seen before include "Hybrid offsprings of a male donkey and a female horse" , "Obstinate people" , "Beasts of burden" , "Backless slippers" , "Offspring of male donkeys and female horses" .)