Complete roadside bomb connected (6)
I believe the answer is:
allied
'connected' is the definition.
(I've seen this in another clue)
'complete roadside bomb' is the wordplay.
'complete' becomes 'all' (similar in meaning).
'roadside bomb' becomes 'ied' (improvised explosive device).
'all'+'ied'='ALLIED'
(Other definitions for allied that I've seen before include "Joined by treaty or agreement" , "Affiliated" , "Joined by, eg, treaty" , "in concert" , "Connected, related" .)