Condemn explosion (5)
I believe the answer is:
blast
I believe this clue is a double definition.
'condemn' is the first definition.
(to blast is to severely criticise)
'explosion' is the second definition.
(blast is a kind of explosion)
(Other definitions for blast that I've seen before include "Shoot" , "Report" , "Blow up with explosives" , "Loud noise from a horn" , "Severely criticise" .)