Soldiers in retreat? No, Sir ragtag army is (8)
I believe the answer is:
garrison
'ragtag army is' is the definition.
I can't judge whether this defines the answer.
'soldiers in retreat? no sir' is the wordplay.
'soldiers in' becomes 'gar' (I can't explain this - if you can you should believe this answer much more).
'retreat?' says the letters should be written in reverse (I've seen 'retreat' mean this).
'no'+'sir'='nosir'
'nosir' back-to-front is 'rison'.
'gar'+'rison'='GARRISON'
Can you help me to learn more?
(Other definitions for garrison that I've seen before include "Military base" , "(Soldiers stationed to guard) fortified place" , "Fortified military post" , "army base?" , "Station (troops) in a town" .)