Fine soldiers getting a gun out (5)
I believe the answer is:
great
'fine' is the definition.
(thesaurus)
'soldiers getting a gun out' is the wordplay.
'soldiers' becomes 'RE' (Royal Engineers).
'getting a gun' becomes 'gat' (I can't justify this - if you can you should believe this answer much more).
'out' is an insertion indicator.
're' inserted into 'gat' is 'GREAT'.
Can you help me to learn more?
(Other definitions for great that I've seen before include "Large, important" , "Chief - weighty" , "Big, large" , "Dickens novel about Pip" , "Considerably above average" .)