Excellent drink taken with army engineers (7)
I believe the answer is:
supreme
'excellent' is the definition.
(thesaurus)
'drink taken with army engineers' is the wordplay.
'drink' becomes 'sup' (I've seen this before).
'taken with' is a charade indicator (letters next to each other).
'army engineers' becomes 'reme' (I am not sure about this - if you are sure you should believe this answer much more).
'sup'+'reme'='SUPREME'
Can you help me to learn more?
(Other definitions for supreme that I've seen before include "Most important" , "Best of all" , "topmost level" , "God" , "Highest in rank - incomparable" .)