Admires new weapon (7)
I believe the answer is:
Here is my best explanation:
'weapon' is the definition.
'admires new' is the subsidiary indication.
'new' is an anagram indicator.
'admires' is an anagram of 'sidearm'.
(Other definitions for sidearm that I've seen before include "Weapon", "Piece", "Officer may carry this", "weapon" and "One may be fired".)