# propulsion

/pɹəˈpəɫʃən/ (US) · /pɹəpˈʌlʃən/ (UK)

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

## Senses

### 1. the act of pushing forward

noun · CEFR C1 · Technical

the force or process that moves an object forward.

For teachers: the action of driving or pushing forward; the process of propelling an object through a medium.

- The rocket uses powerful engines for propulsion to reach space.
- The spacecraft relies on ion propulsion for long-distance travel, as it is far more fuel-efficient than traditional chemical rockets.

Usage: Often used as an uncountable noun when referring to the general concept of movement.

### 2. a mechanical system

noun · CEFR C1 · Technical

a specific system or engine that makes a vehicle move.

For teachers: a specific mechanism or system, such as an engine or motor, that provides the force for movement.

- The ship's main propulsion failed, leaving the crew stuck at sea.
- Engineers are developing a new nuclear propulsion system that could significantly reduce the time required for a manned mission to Mars.

## Examples

- The rocket uses liquid fuel for propulsion.
- Engineers are developing a new type of electric propulsion to make air travel more sustainable and quiet.
- While traditional ships rely on propellers, some marine animals use jet propulsion by rapidly expelling water to achieve high speeds in short bursts.

---

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.