Firm friends prosper, exporting eastern footwear (10)
I believe the answer is:
wellington
'footwear' is the definition.
(Wellington is an example)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for wellington that I've seen before include "Former PM" , "Bomber" , "NZ capital" , "Statesman" , "Waterproof boot" .)