Army doctor leaves surrounded by foreboding (5)
I believe the answer is:
angst
'foreboding' is the definition.
(thesaurus)
'army doctor leaves surrounded by' is the wordplay.
'army doctor' becomes 'MO' (medical officer).
'leaves' suggests deleting specific letters.
'surrounded by' becomes 'amongst' (I've seen this before).
'amongst' with 'mo' taken away is 'ANGST'.
(Other definitions for angst that I've seen before include "Nonspecific sense of anxiety" , "Horrible feeling" , "Feeling of anxiety or guilt" , "Terrible butterflies" , "Acute sense of remorse" .)