Fool English soldier, concealing a weapon (7)
I believe the answer is:
assegai
'weapon' is the definition.
(assegai is a kind of weapon)
'fool english soldier concealing a' is the wordplay.
'fool' becomes 'ass' (ass is a kind of fool).
'english' becomes 'e' (abbreviation).
'soldier' becomes 'gi' (GI can mean a US soldier).
'concealing' indicates putting letters inside.
'gi' going around 'a' is 'gai'.
'ass'+'e'+'gai'='ASSEGAI'
(Other definitions for assegai that I've seen before include "A Zulu war spear" , "African weapon" , "something pointed" , "spear made from wood" , "A Zulu warrior's spear" .)