Umbrella used by soldier, so large (7)
I believe the answer is:
parasol
'umbrella' is the definition.
(I've seen this before)
'by soldier so large' is the wordplay.
'by' says to put letters next to each other.
'soldier' becomes 'para' (short for paratrooper).
'large' becomes 'L' (eg in clothes sizes).
'para'+'so' is 'paraso'.
'paraso'+'l'='PARASOL'
'used' acts as a link.
(Other definitions for parasol that I've seen before include "protection from the rays" , "It's put up to provide shade" , "Small umberella for sun" , "Fair-weather umbrella" , "aeroplane" .)