Comfort found in herbal medicine (4)
I believe the answer is:
balm
'comfort' is the definition.
(I've seen this before)
'in herbal medicine' is the wordplay.
'in' indicates a hidden word.
'BALM' is hidden within 'herbal medicine'.
'found' is the link.
(Other definitions for balm that I've seen before include "Soothing herb" , "skin cream" , "Soothing stuff for lamb" , "Something soothing" , "It comforts, soothes" .)