Herb that's never been used (4)
I believe the answer is:
mint
'herb' is the definition.
(I know that mint is a type of herb)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for mint that I've seen before include "Culinary herb" , "Vast sum of money" , "and 18 Down: Southern US cocktail" , "Plant - in perfect condition" , "sweet > factory?" .)