Revolutionary list observed -- it could be explosive (9)
I believe the answer is:
detonator
'be explosive' is the definition.
(I've seen this in another clue)
'revolutionary list observed' is the wordplay.
'revolutionary' says the letters should be written backwards.
'list' becomes 'rota' (rota is a kind of list).
'observed' becomes 'noted' ('note' can be a synonym of 'observe').
'rota'+'noted'='rotanoted'
'rotanoted' in reverse letter order is 'DETONATOR'.
'it could' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for detonator that I've seen before include "One sets off bang" , "That has explosive effect" , "Explosion starter" , "Device triggering explosives" , "cap" .)