# propellant

/pɹəˈpɛɫənt/ (US) · /pɹəpˈɛlənt/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/propellant
Updated: 2026-05-19

## Definition

a substance that causes something to move or explode. You usually see this word when talking about things like rockets, guns, or fire extinguishers.

For teachers: a substance that provides the force necessary to move an object or cause an explosion. Often refers to the chemical mixture used in firearms or the gas used to propel a rocket.

## Examples

- The rocket uses liquid hydrogen as a propellant.
- The technician checked the propellant levels in the fire extinguisher before the flight took off.
- Modern aerospace engineering focuses on developing more efficient propellants that provide greater thrust while minimizing the environmental impact of combustion byproducts.

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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.