Airborne soldier in suitable American machine (9)
I believe the answer is:
apparatus
'machine' is the definition.
(thesaurus)
'airborne soldier in suitable american' is the wordplay.
'airborne soldier' becomes 'para' (I've seen this before).
'in' is an insertion indicator.
'suitable' becomes 'apt' (I've seen this before).
'american' becomes 'us'.
'para' inserted into 'apt' is 'apparat'.
'apparat'+'us'='APPARATUS'
(Other definitions for apparatus that I've seen before include "Tackle" , "Collection of equipment designed for a particular purpose" , "Piece of equipment" , "Technical kit" , "Set of equipment serving a specific purpose" .)