The most common and most likely answer to this crossword clue is the 12 letter word DISAGREEMENT
I've seen this crossword clue in The Daily Telegraph
D
I
S
A
G
R
E
E
M
E
N
T
More clues leading to the result DISAGREEMENT
- Row of dim teenagers in need of correction
- Greediest man involved in quarrel
- Hellish situation before a welcome with chaps in altercation
- Row of detectives with squad in a salute
- Key meetings are disrupted by conflict
- Beef, meat and greens I’d cooked
- Emerge in sad shambles with time difference
- Argument made steering awkward
- Trouble is generated about money — producing this?
Buddy explains!

The straight part
We know that "Beef" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case beef = disagreement.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 DISAGREEMENT mean?
DISAGREEMENT noun- An argument or debate.
- A condition of not agreeing or concurring.