Relieving girl in hospital department (9)
I believe the answer is:
emollient
'relieving' is the definition.
(thesaurus)
'girl in hospital department' is the wordplay.
'girl' becomes 'mollie' (**).
'in' is an insertion indicator.
'hospital department' becomes 'ent'.
'mollie' going inside 'ent' is 'EMOLLIENT'.
(Other definitions for emollient that I've seen before include "soothing agent" , "Stuff that softens or soothes the skin" , "Soothing, calming" , "Intended to pacify girl" , "Balm" .)