The most common and most likely answer to this crossword clue is the 9 letter word RESPONDED
I've seen this crossword clue in The Daily Telegraph
R
E
S
P
O
N
D
E
D
Buddy explains!

The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does RESPONDED mean?
RESPONDED verb- To say something in return; to answer; to reply.
- To act in return; to carry out an action or in return to a force or stimulus; to do something in response.
- To correspond with; to suit.
- To satisfy; to answer.
- To be liable for payment.