# barrier

/ˈbæɹiɝ/ (US) · /bˈæɹɪɐ/ (UK)

Source: https://englishreference.com/word/barrier
Updated: 2026-06-19

## Senses

### 1. physical obstruction

noun · CEFR B1

a physical object like a fence or wall that stops people or vehicles from passing.

For teachers: a physical structure or object that prevents movement or separates two areas.

- The police put up a metal barrier to keep the crowd away from the stage.
- Concrete barriers were installed along the highway to prevent vehicles from crossing into the path of oncoming traffic during the construction phase.

### 2. abstract obstacle

noun · CEFR B2

a rule, situation, or problem that prevents someone from doing something or succeeding.

For teachers: an abstract circumstance or obstacle that impedes progress, communication, or social integration.

- The high cost of university can be a major barrier for many students.
- Language barriers often hinder effective collaboration between international teams, even when all members share a common technical background.

### 3. biological membrane

noun · CEFR C1 · Technical

a layer in the body that lets some things in but keeps harmful things out.

For teachers: a physiological structure, such as the blood-brain barrier, that regulates the passage of substances between different compartments of the body.

- The skin acts as a natural barrier against germs and infections.
- The blood-brain barrier is highly selective, protecting the central nervous system from potentially neurotoxic substances circulating in the blood.

### 4. to block

verb · CEFR C1 · Formal

to close off or block a place using a barrier.

For teachers: to obstruct or enclose a space by means of a physical barrier. Transitive use is less common than the noun form.

- Workers began to barrier the construction site to keep the public safe.
- The authorities decided to barrier the entrance to the cave after several hikers became lost in the unmapped tunnels.

## Examples

- The police put up a barrier to block the road.
- A lack of confidence can be a significant barrier to success when you are starting a new career.
- The trade agreement aims to remove every regulatory barrier that currently prevents small businesses from exporting their goods to neighboring markets.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.