Outfit of crack soldiers seen in film (9)
I believe the answer is:
equipment
'outfit' is the definition.
(thesaurus)
'crack soldiers seen in film' is the wordplay.
'crack' becomes 'quip' ('quip' can be a synonym of 'crack'**).
'soldiers' becomes 'men' (I've seen this before).
'seen in' is an insertion indicator.
'film' becomes 'et'.
'quip'+'men'='quipmen'
'quipmen' placed into 'et' is 'EQUIPMENT'.
'of' acts as a link.
(Other definitions for equipment that I've seen before include "Items needed for a particular purpose" , "Kit, apparatus" , "Apparatus, tools" , "fitting" , "outfit" .)