A nobleman's fists? (5)
I believe the answer is:
dukes
'a nobleman's fists?' is the definition.
'dukes' can be an answer for 'fists?' (I've seen this in another clue). I'm not certain of the 'a nobleman's' bit.
'nobleman's fists?' is the wordplay.
'nobleman' becomes 'duke' (duke is a kind of nobleman).
'fists?' becomes 's' (I can't justify this - if you can you should give a lot more credence to this answer).
'duke'+'s'='DUKES'
Can you help me to learn more?
(Other definitions for dukes that I've seen before include "Noblemen" , "Peers of the realm" , "Titled gents or slangy fists" , "eg 21, 22 and Plaza-Toro" .)