The most common and most likely answer to this crossword clue is the 6 plus 4 letter word BARBED WIRE
I've seen this crossword clue in The Sunday Telegraph
B
A
R
B
E
D
W
I
R
E
More clues leading to the result BARBED WIRE
- Message that's wounding? This sitting on the fence?
- , 24 down Sarcastic communication that was and is painful to get over
- Pub brewed, I suspect, something spiky and difficult to get through
- Material for fencing in rabbit mostly, with deer running around bungalow’s rear
- Hurtful old kind of message that creates barrier
- Sharply worded cable warning to keep out
Buddy explains!

The straight part
We know that "barrier" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case barrier = barbed wire.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.