# breakthrough

/ˈbɹeɪkˌθɹu/ (US) · /bɹˈeɪkθɹuː/ (UK)

Source: https://englishreference.com/word/breakthrough
Updated: 2026-06-20

## Senses

### 1. major discovery

noun · CEFR B2

a sudden and important discovery or success, especially in science or medicine.

For teachers: a significant and often sudden advance or discovery that overcomes a major obstacle or impasse.

- Scientists have made a major breakthrough in the treatment of the disease.
- The research team announced a significant breakthrough in battery technology, potentially doubling the range of electric vehicles within the next decade.

### 2. military/sports penetration

noun · CEFR C1 · Formal

the act of breaking through a line of defense, like in a war or a game.

For teachers: the act of penetrating an opponent's defensive line or fortifications.

- The army achieved a breakthrough after weeks of fighting at the border.
- The striker's sudden breakthrough in the final minutes of the match caught the defenders completely off guard.

### 3. highly successful

adjective · CEFR B2

describing a success that makes someone famous or shows great progress.

For teachers: characterised by major progress or marking a significant transition to a higher level of success or recognition.

- The young actress had her breakthrough role in a popular TV drama.
- Following several years of modest sales, the band finally achieved breakthrough success with their third studio album.

### 4. medical infection after vaccine

adjective · CEFR C1 · Technical

describing an illness that someone catches even though they were vaccinated against it.

For teachers: relating to the contraction of a disease by an individual who has been vaccinated or has existing immunity.

- The doctor explained that breakthrough infections are usually very mild.
- Public health officials monitored the rate of breakthrough cases to determine if the vaccine's efficacy was waning over time.

Usage: Usually modifies 'infection' or 'case'.

## Examples

- Scientists made a major breakthrough in cancer research this year.
- After months of failed negotiations, the two countries finally reached a diplomatic breakthrough regarding the border dispute.
- The team's recent breakthrough in quantum computing could potentially render current encryption methods obsolete within a decade.

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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.