Soldiers get old large umbrella (7)
I believe the answer is:
parasol
'umbrella' is the definition.
(I know that parasol is a type of umbrella)
'soldiers get old large' is the wordplay.
'soldiers' becomes 'paras' (para is a kind of soldier).
'get' is a charade indicator (letters next to each other).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'large' becomes 'L' (eg in clothes sizes).
'paras'+'o'+'l'='PARASOL'
(Other definitions for parasol that I've seen before include "aeroplane" , "mushroom" , "Protection from light" , "Desert Shield?" , "for protection from the elements" .)