The most common and most likely answer to this crossword clue is the 8 letter word PROHIBIT
I've seen this crossword clue in The Daily Telegraph
P
R
O
H
I
B
I
T
More clues leading to the result PROHIBIT
- Ban for greeting segment
- Stop for welcome morsel
- Expert to welcome short snack in bar
- Greek character’s piece about men reversing ban
- Rebuilt hip bistro must ignore small bar
- Ban for Hungary initially took effect after international
- Ban for husband took effect after one
- Orbit — hip new bar
- Bar backing Scottish team losing final to Italian
- Publicist I got my teeth into outside hotel bar
Buddy explains!

The straight part
We know that "Ban" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ban = prohibit.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 PROHIBIT mean?
PROHIBIT verb- To forbid, disallow, or proscribe officially; to make illegal or illicit.