# assertion

/əˈsɝʃən/ (US) · /ɐsˈɜːʃən/ (UK)

Source: https://englishreference.com/word/assertion
Updated: 2026-07-22

## Senses

### 1. a strong claim

noun · CEFR C1 · Academic · Formal

a statement where you say something is true, often with a lot of confidence.

For teachers: a confident and forceful statement of fact or belief, often made without immediate proof.

- The lawyer made an assertion that his client was innocent of the crime.
- The author's central assertion is that economic stability depends more on psychological factors than on physical resources.

Usage: Often followed by a 'that' clause or the preposition 'of'.

### 2. insisting on a right

noun · CEFR C1 · Formal

the act of making sure your rights or power are recognized.

For teachers: the act of asserting or insisting upon one's rights, authority, or influence.

- The small country's assertion of its independence surprised the world.
- The sudden assertion of executive power by the board led to a series of resignations among the senior management team.

### 3. programming check

noun · CEFR C2 · Technical

a command in a computer program that checks if a condition is true while the code is running.

For teachers: a boolean expression at a specific point in a program which will be true unless there is a bug in the code.

- The programmer added an assertion to make sure the user's age was not a negative number.
- If the assertion fails during the execution of the test suite, the program will terminate immediately to prevent further data corruption.

Usage: Commonly used in the context of 'failed assertion' or 'assertion error'.

### 4. audit claim

noun · CEFR C2 · Technical · Formal

a claim made by a company about its money that an accountant checks.

For teachers: a representation or declaration made by management regarding the recognition, measurement, and presentation of items in financial statements.

- The auditor checked the company's assertion that it owned all the equipment listed.
- The audit team must obtain sufficient evidence to support management's assertion regarding the valuation of intangible assets.

## Examples

- She made a bold assertion about the company's future.
- The lawyer's assertion that the witness was lying changed the mood of the entire trial.
- While the author provides plenty of anecdotal evidence, the central assertion of the book remains unsupported by any peer-reviewed data or statistical analysis.

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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.