The most common and most likely answer to this crossword clue is the 8 letter word REPLYING
I've seen this crossword clue in The Daily Telegraph
R
E
P
L
Y
I
N
G
More clues leading to the result REPLYING
Buddy explains!
The straight part
We know that "Riposting" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case riposting = replying.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 REPLYING mean?
REPLYING verb- To give a written or spoken response, especially to a question, request, accusation or criticism; to answer.
- To act or gesture in response.
- To repeat something back; to echo.