The most common and most likely answer to this crossword clue is the 6 letter word FIERCE
I've seen this crossword clue in The Guardian
F
I
E
R
C
E
More clues leading to the result FIERCE
- Violent prick going quiet to loud
- Ferocious fire destroyed empty campsite
- Wild fire damaged church
- Wild fellow that is about to take cocaine
- Violent secret life uncovered when looking back
- Intense fellow that is rector with Anglicans
- Feisty qualifier celebrated inclusion
- Wild reef and endless ice spell disaster
- Savage, caustic old author taking new lead
- Wild stab, making piano loud
Buddy explains!

The straight part
We know that "Violent" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case violent = fierce.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 FIERCE mean?
FIERCE adjective- Exceedingly violent, severe, ferocious, cruel or savage.
- Resolute or strenuously active.
- Threatening in appearance or demeanor.
- (rural) Excellent, very good.
- Of exceptional quality, exhibiting boldness or chutzpah.
- (rural) Extremely; very.