Pop, explode (5)
I believe the answer is:
burst
I believe this is a double definition.
'pop' is the first definition.
(I've seen this before)
'explode' is the second definition.
(synonyms)
(Other definitions for burst that I've seen before include "Split asunder" , "Collapse" , "Puncture, explode" , "Ruptured" , "Explode (as 1 acrosses do)" .)