Beneath airborne soldier, spot a drone? (8)
I believe the answer is:
parasite
'a drone?' is the definition.
(thesaurus)
'beneath airborne soldier spot' is the wordplay.
'beneath' means one lot of letters go next to another (in a down clue).
'airborne soldier' becomes 'para' (I've seen this before).
'spot' becomes 'site' (I've seen this before**).
'para' put next to 'site' is 'PARASITE'.
(Other definitions for parasite that I've seen before include "Relies on host to survive" , "Creature that lives off others" , "Organism living off another" , "Say mistletoe" , "Organism that lives on another" .)