Soldier wearing suitable American gear (9)
I believe the answer is:
apparatus
'gear' is the definition.
(thesaurus)
'soldier wearing suitable american' is the wordplay.
'soldier' becomes 'para' (para is a kind of soldier**).
'wearing' indicates putting letters inside.
'suitable' becomes 'apt' (I've seen this before).
'american' becomes 'us'.
'para' inserted inside 'apt' is 'apparat'.
'apparat'+'us'='APPARATUS'
(Other definitions for apparatus that I've seen before include "Piece of equipment" , "Set of equipment serving a specific purpose" , "Equipment, gear" , "Equipment designed for a specific function" , "Technical kit" .)