Soldier wearing suitable American equipment (9)
I believe the answer is:
apparatus
'equipment' is the definition.
(apparatus can mean pieces of equipment)
'soldier wearing suitable american' is the wordplay.
'soldier' becomes 'para' (short for paratrouper).
'wearing' means one lot of letters goes inside another.
'suitable' becomes 'apt' (I've seen this before).
'american' becomes 'us' (abbreviation for United States).
'para' inserted inside 'apt' is 'apparat'.
'apparat'+'us'='APPARATUS'
(Other definitions for apparatus that I've seen before include "Set of equipment serving a specific purpose" , "Group of parts that work together to perform a function" , "Technical equipment" , "Tackle" , "Equipment designed for a specific function" .)