Singular kind of money (6)
I believe the answer is:
specie
'money' is the definition.
(I've seen this before)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for specie that I've seen before include "Coin as opposed to paper money" , "Money in the form of coin" , "Money as coins" , "Coins collectively" , "Coinage, metal money" .)