Murmured British union representative initially exploited (7)
I believe the answer is:
burbled
'murmured' is the definition.
Although both the answer and definition are past participle verbs, I cannot understand how they can define each other.
'british union representative initially exploited' is the wordplay.
'initially' suggests taking the first letters.
'exploited' becomes 'bled' (I can't explain this - if you can you should give a lot more credence to this answer).
The first letters of 'british union representative' is 'bur'.
'bur'+'bled'='BURBLED'
Can you help me to learn more?
(Another definition for burbled that I've seen is " Gurgled, as a river".)