Officer in A & E the writer would flee? (4-2-4)
I believe the answer is:
aide-de-camp
'officer' is the definition.
(aide-de-camp is a kind of officer)
'in a e the writer would flee?' is the subsidiary indication.
'in' is an insertion indicator.
'the writer' becomes 'i' (the person who is writing these clues).
'would' becomes 'd' (I've seen this in other clues).
'flee?' becomes 'decamp' (decamping is a kind of fleeing**).
'a'+'e'='ae'
'i'+'d'='id'
'ae' going around 'id' is 'aide'.
'aide'+'decamp'='aidedecamp'
(Other definitions for aide-de-camp that I've seen before include "Military assistant" , "Senior officer's assistant" , "Military adviser" .)