The most common and most likely answer to this crossword clue is the 9 letter word COMBATIVE
I've seen this crossword clue in The Daily Telegraph
C
O
M
B
A
T
I
V
E
More clues leading to the result COMBATIVE
- Aggressive commanding officer and doctor show up
- Pugnacious player at crease getting four – word of disapproval about that?
- Arrive outside club accompanied by one very pugnacious
- Mob active, violent and aggressive
- Challenging search has local resident heading off
- Evict a mob in a riot, being antagonistic?
Buddy explains!
The straight part
We know that "antagonistic" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case antagonistic = combative.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 COMBATIVE mean?
COMBATIVE adjective- Given to fighting; disposed to engage in combat; pugnacious.