The most common and most likely answer to this crossword clue is the 7 letter word TALIBAN
I've seen this crossword clue in The Times
T
A
L
I
B
A
N
More clues leading to the result TALIBAN
- Fundamentalist movement I outlaw after short conference
- Function without a liberal fundamentalist
- Extremist born in leaderless 24
- Starts to take alcoholic liquor in prohibition? They won’t like it
- Political fundamentalists, a party to keep in the shade
- Fundamentalist group beat walls in defence, endlessly
- Tabloid regularly interjects: ‘Time to outlaw fundamentalists!’
- Battalion not to become a medieval force
- In Afghanistan, a bilateral withdrawing sees new rulers
- Turkey’s leader and caliph outlaw Islamist group
Buddy explains!

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.