Again tried to pass back small weapons (6)
I believe the answer is:
tasers
'weapons' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'again tried to pass back small' is the wordplay.
'again tried to pass' becomes 'resat' (sat an exam again).
'back' says the letters should be written backwards.
'small' becomes 's' (abbreviation - e.g. clothes size).
'resat' written backwards gives 'taser'.
'taser'+'s'='TASERS'
Can you help me to learn more?
(Other definitions for tasers that I've seen before include "Stun guns" , "Paralysing arms" .)