Enlisted man to see detective (7,3)
I believe the answer is:
private eye
'detective' is the definition.
(thesaurus)
'enlisted man to see' is the wordplay.
'enlisted man' becomes 'private' (private is a kind of enlisted man).
'to see' becomes 'eye' (I've seen this before).
'private'+'eye'='PRIVATE EYE'
(Other definitions for private eye that I've seen before include "Spade, say" , "Freelance detective" , "50 today" , "Periodical" , "Satirical magazine - undercover detective" .)