The most common and most likely answer to this crossword clue is the 10 letter word NORTH-WEST
I've seen this crossword clue in Financial Times
N
O
R
T
H
-
W
E
S
T
Buddy explains!
The straight part
We know that "opponents" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case opponents = north-west.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 NORTH-WEST mean?
NORTH-WEST noun- The compass point halfway between north and west, bearing 315°, abbreviated as NW.