Matters for noblemen (6)
I believe the answer is:
counts
This clue could be a double definition.
'matters for' is the first definition.
'counts' can be an answer for 'matters' (count can mean to matter or be significant). I'm not certain of the 'for' bit.
'noblemen' is the second definition.
(count is a kind of nobleman)
Can you help me to learn more?
(Other definitions for counts that I've seen before include "Enumerates like minor aristocracy" , "Numbers" , "Determines the number of" .)