In angry cry of pain start to brandish weapon (8)
I believe the answer is:
crossbow
'weapon' is the definition.
(crossbow is a kind of weapon)
'in angry cry of pain start to brandish' is the wordplay.
'in' means one lot of letters goes inside another.
'angry' becomes 'cross' (I've seen this before).
'cry of pain' becomes 'ow' (I've seen this in other clues).
'start to' suggests taking the first letters.
The initial letter of 'brandish' is 'b'.
'cross'+'ow'='crossow'
'crossow' placed around 'b' is 'CROSSBOW'.
(Other definitions for crossbow that I've seen before include "can precipitate a quarrel" , "historic weapon" , "Missile-launcher" , "Weapon firing bolts" , "Old weapon of war" .)