Herbal infusion (6)
I believe the answer is:
tisane
'herbal infusion' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tisane that I've seen before include "Infusion (eg of herbs or flowers)" , "Infusion of e.g. dried or fresh flowers or leaves" , "Herb tea" , "brew" , "Herb-tea" .)