Airborne soldier in suitable American gear (9)
I believe the answer is:
apparatus
'gear' is the definition.
(I've seen this before)
'airborne soldier in suitable american' is the wordplay.
'airborne soldier' becomes 'para' (paratrooper).
'in' indicates putting letters inside.
'suitable' becomes 'apt' (apt means appropriate or fitting).
'american' becomes 'US' (United States).
'para' placed within 'apt' is 'apparat'.
'apparat'+'us'='APPARATUS'
(Other definitions for apparatus that I've seen before include "Piece of equipment" , "Horse, maybe" , "Machinery" , "Set of equipment serving a specific purpose" , "Technical equipment" .)