Silenced and told the heartless rat off (9)
I believe the answer is:
throttled
'silenced' is the definition.
The answer and definition can be both related to change as well as being past participle verbs.
Perhaps you can see an association between them that I can't see?
'told the heartless rat off' is the wordplay.
'heartless' says to hollow out the word (remove centre letters).
'off' indicates anagramming the letters.
'rat' with its middle removed is 'rt'.
'told'+'the'+'rt'='toldthert'
'toldthert' anagrammed gives 'THROTTLED'.
'and' is the link.
Can you help me to learn more?
(Other definitions for throttled that I've seen before include "Strangled manually" , "Choked" , "Suppressed" .)