Meaning of “barrier” - Learner’s Dictionary

barrier

noun [ C ] uk us /ˈbæriər/
FENCE

B2 a type of fence that prevents people from going into an area:

Police erected barriers to hold back the crowd.
LIMIT

B2 something that prevents people from doing what they want to do:

Kim is taking Spanish lessons in an attempt to overcome the language barrier.
Shyness is a big barrier to making friends.
→ See also crash barrier

(Definition of “barrier” from the Cambridge Learner’s Dictionary © Cambridge University Press)