The most common and most likely answer to this crossword clue is the 12 letter word PLEA-BARGAIN
I've seen this crossword clue in The Times
P
L
E
A
-
B
A
R
G
A
I
N
Buddy explains!
The straight part
We know that "legal discussion" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case legal discussion = plea-bargain.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 PLEA-BARGAIN mean?
PLEA-BARGAIN noun- An agreement between a defendant and the prosecution in which the defendant agrees to a plea such as guilty or nolo contendere to a lesser charge rather than contesting a greater charge.
- To make an agreement in which a defendant agrees to plead guilty to a lesser charge instead of not guilty to a greater one.