Curse an explosion (5)
I believe the answer is:
blast
I believe this is a double definition.
'curse' is the first definition.
(thesaurus)
'explosion' is the second definition.
(blast is a kind of explosion)
'an' is the link.
(Other definitions for blast that I've seen before include "Strong gust of air" , "Blow up with explosives" , "slate" , "Severely criticise" , "Loud noise from a horn" .)