Former copper beginning to erupt, go ballistic! (7)
I believe the answer is:
explode
'former copper beginning to erupt go ballistic' is the definition.
I can't tell whether this definition defines the answer.
'former copper beginning to erupt' is the wordplay.
'former' becomes 'ex' (prefix meaning former or onetime).
'copper' becomes 'plod' (both are slang terms for a police officer).
'beginning to' indicates taking the first letters.
The initial letter of 'erupt' is 'e'.
'ex'+'plod'+'e'='EXPLODE'
Can you help me to learn more?
(Other definitions for explode that I've seen before include "Detonate" , "Violently shatter" , "Pop" , "Blow up" , "Burst violently" .)