Authorisation to work with soldiers in hospital department (9)
I believe the answer is:
enactment
'authorisation' is the definition.
'work with soldiers in hospital department' is the wordplay.
'work with' becomes 'act' ('act' can be a synonym of 'work'. I am not sure about the 'with' bit.**).
'soldiers' becomes 'men' (I've seen this before).
'in' is an insertion indicator.
'hospital department' becomes 'ent'.
'act'+'men'='actmen'
'actmen' inserted within 'ent' is 'ENACTMENT'.
'to' is the link.
(Other definitions for enactment that I've seen before include "A played-out" , "Theatrical performance" , "Legal process" , "Command" , "Law that's been passed" .)