In herbal medicine, something soothing (4)
I believe the answer is:
balm
'something soothing' is the definition.
(cream that soothes skin)
'in herbal medicine' is the wordplay.
'in' says the answer is hidden in the clue.
'BALM' is hidden within 'herbal medicine'.
(Other definitions for balm that I've seen before include "Soothing herb" , "that will soothe the skin" , "Royal holiday residence on the River Dee" , "It comforts, soothes" , "It's comforting" .)