The most common and most likely answer to this crossword clue is the 8 letter word SUPPRESS
I've seen this crossword clue in The Daily Telegraph
S
U
P
P
R
E
S
S
More clues leading to the result SUPPRESS
- Put down drink, getting squash
- Drink with the mob and black out
- Drink journalists keep down
- Drink with journalists to keep out of the news?
- Squash and second form of exercise switched
- Journalists on drink, possibly squash?
- Control reporters on drink
- . Censor on state media after carrying headline on scandal
- Crush given drink by force
- Control reporters with drink
Buddy explains!

The straight part
We know that "keep down" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case keep down = suppress.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 SUPPRESS mean?
SUPPRESS verb- To put an end to, especially with force, to crush, do away with; to prohibit, subdue.
- To restrain or repress, such as laughter or an expression.
- To exclude undesirable thoughts from one's mind.
- To prevent publication.
- To stop a flow or stream.
- To forbid the use of evidence at trial because it is improper or was improperly obtained.
- To reduce unwanted frequencies in a signal.
- To hold in place, to keep low.