Herb in excellent condition (4)
I believe the answer is:
mint
This clue is a double definition.
'herb' is the first definition.
(I know that mint is a type of herb)
'excellent condition' is the second definition.
(I've seen this in another clue)
'in' is the link.
(Other definitions for mint that I've seen before include "Large sum of money" , "Coin-making place or nice lamb sauce" , "Forge" , "Where money is made by the government" , "Where money coins are manufactured" .)