Soldiers holding deserter without charge (6)
I believe the answer is:
gratis
'without charge' is the definition.
(thesaurus)
'soldiers holding deserter' is the wordplay.
'soldiers' becomes 'gis' (I've seen this in other clues**).
'holding' means one lot of letters goes inside another.
'deserter' becomes 'rat' (I've seen this before).
'gis' placed around 'rat' is 'GRATIS'.
(Other definitions for gratis that I've seen before include "not charged" , "Free (Latin)" , "On the house" , "Free, at no cost" , "Free, costs nothing" .)