# identifier

/aɪˈdɛntəˌfaɪɝ/ (US) · /aɪdˈɛntɪfˌaɪə/ (UK) · CEFR B2 · Noun

Source: https://englishreference.com/word/identifier
Updated: 2026-05-08

## Definition

a unique name or label used to recognize a specific person or thing. In computing, it is the name you give to a variable or a piece of data.

For teachers: a sequence of characters used to uniquely distinguish an entity within a specific system or context. In programming, it refers to the user-defined name of a variable, function, or class.

## Examples

- Each user has a unique identifier in the database.
- The compiler threw an error because the identifier started with a number, which violates the language's naming rules.
- To maintain data integrity across the distributed system, the architecture assigns a globally unique identifier to every transaction, ensuring no two records can ever be confused during synchronization.

## Usage notes

- Commonly used in technical contexts; often abbreviated as 'ID' in informal speech or documentation.

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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.