The most common and most likely answer to this crossword clue is the 6 letter word OUTLAW
I've seen this crossword clue in Financial Times
O
U
T
L
A
W
More clues leading to the result OUTLAW
- Hood, for example? Old hat originally worn around city
- Oxford University sent up Disney’s Robin Hood?
- You start off by reversing Disney ban
- Criminal on parole perhaps, cut grass
- Make illegal Open University Disney retrospective
- Ban Bonnie or Clyde?
- Bar where French dance returns endlessly
- Where anyone can study review of Disney’s Robin Hood?
- Criminal rights of openly gay people?
- Ban over cinema classification Disney rejected
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 = outlaw.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 OUTLAW mean?
OUTLAW noun- A fugitive from the law.
- (history) A criminal who is excluded from normal legal rights; one who can be killed at will without legal penalty.
- A person who operates outside established norms.
- A wild horse.
- An in-law: a relative by marriage.
- One who would be an in-law except that the marriage-like relationship is unofficial.
- A prostitute who works alone, without a pimp.
- To declare illegal.
- To place a ban upon.
- To remove from legal jurisdiction or enforcement.
- To deprive of legal force.