# retardant

/ɹiˈtɑɹdənt/ (US) · /ɹɪtˈɑːdənt/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/retardant
Updated: 2026-10-16

## Definition

a chemical that slows down fire or makes something harder to burn. You find it in clothes, furniture, and sprays firefighters use.

For teachers: a substance that inhibits or delays a chemical process, most commonly combustion. Most frequently encountered in phrases such as 'fire retardant' or 'flame retardant'.

## Examples

- This jacket has a fire retardant coating.
- Firefighters spray retardant ahead of the wildfire to stop the flames from reaching the houses.
- The new building code requires timber treated with retardant in all high-rise balconies after investigators linked the rapid spread of the blaze to untreated cladding.

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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.