Somewhat asinine footwear? (5)
I believe the answer is:
mules
'footwear?' is the definition.
(mules is a kind of footwear)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for mules that I've seen before include "Offspring of male donkeys and female horses" , "Stubborn horse-donkey animaly" , "Hybrid offsprings of a male donkey and a female horse" , "Obstinate people" , "Backless slippers" .)