Given caution, unless given makeshift bomb (8)
I believe the answer is:
notified
'given caution' is the definition.
The definition and answer can be both to do with communicating as well as being past participle verbs.
Maybe there's a link between them I don't understand?
'unless given makeshift bomb' is the wordplay.
I cannot really see how this works, but
'bomb' could be 'ied' (abbreviation for improvised explosive device) and 'ied' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for notified that I've seen before include "Officially informed" , "Told, informed" , "Informed, reported to" , "Formally informed" .)