Soothing ointment used in some herbal medicines (4)
I believe the answer is:
balm
'soothing ointment' is the definition.
(I've seen this before)
'in some herbal medicines' is the wordplay.
'in' indicates the answer is hidden within the clue.
'BALM' is hidden in the letters of 'some herbal medicines'.
'used' acts as a link.
(Other definitions for balm that I've seen before include "skin cream" , "Unguent" , "Soothing ointment for lamb (4)" , "Soothing substance" , "It comforts, soothes" .)