Soothing application (4)
I believe the answer is:
aloe
'soothing application' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for aloe that I've seen before include "Bitter drug from a leaf juice" , "Succulent plant (may be bitter!)" , "O, ale with bitter plant" , "Bitter fruit" , "shrub" .)