The most common and most likely answer to this crossword clue is the 9 letter word ROADBLOCK
R
O
A
D
B
L
O
C
K
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 = roadblock.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 ROADBLOCK mean?
ROADBLOCK noun- Something that blocks or obstructs a road.
- An obstacle or impediment.
- To prevent, hinder.