Train ’em to use a turret (7)
I believe the answer is:
minaret
'a turret' is the definition.
(thesaurus)
'train 'em to use' is the wordplay.
'to use' indicates anagramming the letters (I've seen 'used' mean this).
'train'+'em'='trainem'
'trainem' with letters rearranged gives 'MINARET'.
(Other definitions for minaret that I've seen before include "Muezzin's tower" , "Raiment worn on mosque tower" , "religious tower" , "Building" , "Slim tower of a mosque" .)