Small group of letters can be a weapon (5)
I believe the answer is:
sword
'weapon' is the definition.
(I know that sword is a type of weapon)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for sword that I've seen before include "Combat" , "Weapon with long blade" , "Bladed weapon" , "Weapon of steel" , "Double-edged weapon" .)