Cossacks are husky chaps, one hears (8)
I believe the answer is:
horsemen
'one hears' is the definition.
I can't judge whether this defines the answer.
'cossacks are husky chaps' is the wordplay.
I cannot quite see how this works, but
'chaps' could be 'men' (chap means a man) and 'men' is found in the answer.
The remaining letters 'horse' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for horsemen that I've seen before include "knights, perhaps" , "Riders" , "The Bible has Four . . . . . . . . of the Apocalypse" .)