Assault; seizure (6)
I believe the answer is:
attack
I believe this is a double definition.
'assault' is the first definition.
(I know that assault can be written as attack)
'seizure' is the second definition.
(synonyms)
(Other definitions for attack that I've seen before include "Hit out" , "mount an offensive" , "act of aggression" , "Offensive action" , "Start a fight or criticise strongly" .)