Energy held by two tons made a tremendous noise (9)
I believe the answer is:
thundered
'made a tremendous noise' is the definition.
The answer and definition can be both to do with communicating as well as being past participle verbs.
Maybe you can see an association between them that I don't see?
'energy held by two tons' is the wordplay.
'two tons' can mean two substitutions for 'ton'.
'energy' becomes 'e' (physics symbol as in E=mcu).
'held by' means one lot of letters goes inside another.
'ton' becomes 't' (abbreviation).
'ton' becomes 'hundred' (I can't justify this - if you can you should give a lot more credence to this answer).
't'+'hundred'='thundred'
'e' placed into 'thundred' is 'THUNDERED'.
Can you help me to learn more?
(Another definition for thundered that I've seen is " Did like the Times".)