# classifier

/klˈæsɪfˌaɪə/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/classifier
Updated: 2026-10-14

## Definition

a computer program that puts things into groups, like spam and normal email. You train it with examples so it learns to sort new things on its own.

For teachers: a computational model or algorithm that assigns input data to predefined categories or labels. Typically trained on labelled examples to predict the category of new, unseen inputs.

## Examples

- The email classifier moves spam to a separate folder.
- The bank uses a classifier to flag unusual transactions for further review.
- Trained on thousands of labelled images, the classifier distinguishes benign moles from early melanomas with accuracy that rivals junior dermatologists.

## Synonyms

filter, categorizer, sorter

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