Soldiers with wind flinch (6)
I believe the answer is:
recoil
'flinch' is the definition.
(I've seen this before)
'soldiers with wind' is the wordplay.
'soldiers' becomes 're' (Royal Engineers).
'with' means one lot of letters go next to another.
'wind' becomes 'coil' (coiling is a kind of winding**).
're'+'coil'='RECOIL'
(Other definitions for recoil that I've seen before include "Quail is here!" , "Flinch, starts back" , "(As a firearm) spring back" , "withdraw" , "Spring back suddenly as gun may when fired" .)