Remain working as a soldier (6)
I believe the answer is:
marine
'a soldier' is the definition.
(I've seen this before)
'remain working' is the wordplay.
'working' is an anagram indicator.
'remain' anagrammed gives 'MARINE'.
'as' acts as a link.
(Other definitions for marine that I've seen before include "Sea-soldier" , "Member of the forces" , "jolly" , "seaman" , "'Nautical, maritime (6)'" .)