Angry act of submission to a medieval weapon (8)
I believe the answer is:
crossbow
'to a medieval weapon' is the definition.
(I've seen this before)
'angry act' is the wordplay.
'angry' becomes 'cross' (cross can mean annoyed or angry).
'act' becomes 'bow' (bow is a kind of act).
'cross'+'bow'='CROSSBOW'
'of submission' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for crossbow that I've seen before include "Missile-launcher" , "William Tell's weapon" , "Medieval weapon" , "Ancient weapon, shot bolts" , "Old weapon with mechanism for firing arrow" .)