Who may work with horse shoes (8)
I believe the answer is:
trainers
'shoes' is the definition.
(I have seen 'Casual shoes ' mean 'trainers' so perhaps 'shoes' could also mean 'trainers')
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for trainers that I've seen before include "Coaches: leisure footwear" , "Coach's" , "Casual footwear" , "People who coach athletes, or running shoes" , "Those going on foot" .)