The most common and most likely answer to this crossword clue is the 12 letter word COUNTERCLAIM
I've seen this crossword clue in Independent
C
O
U
N
T
E
R
C
L
A
I
M
More clues leading to the result COUNTERCLAIM
Buddy explains!
The straight part
We know that "response to allegation" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case response to allegation = counterclaim.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 COUNTERCLAIM mean?
COUNTERCLAIM noun- A suit filed by a defendant against a plaintiff secondary to the original complaint.
- To file a counterclaim.