Surrounded by soldiers, a deserter gets free! (6)
I believe the answer is:
gratis
'free' is the definition.
('gratis' can be a synonym of 'free')
'surrounded by soldiers a deserter' is the wordplay.
'surrounded by' means one lot of letters goes inside another (I've seen this in other clues).
'soldiers' becomes 'gis' (I've seen this in other clues).
'a deserter' becomes 'rat' (I've seen this before).
'gis' enclosing 'rat' is 'GRATIS'.
'gets' acts as a link.
(Other definitions for gratis that I've seen before include "Free, at no cost" , "Costing nothing, free" , "Free (Latin)" , "not charged" , "Free of charge" .)