# asteroid

/ˈæstɝˌɔɪd/ (US) · /ˈɑːstəɹˌɔɪd/ (UK)

Source: https://englishreference.com/word/asteroid
Updated: 2026-06-20

## Senses

### 1. space rock

noun · CEFR B2

a large piece of rock or metal that moves around the sun, mostly in the space between Mars and Jupiter.

For teachers: a small rocky or metallic body orbiting the sun, typically found in the asteroid belt between Mars and Jupiter.

- Scientists are tracking a large asteroid that will pass close to Earth next month.
- The mission aimed to land a probe on the asteroid's surface to analyse its mineral composition and determine its origin within the early solar system.

### 2. starfish

noun · CEFR C2 · Technical

a sea animal with a flat, star-shaped body and five or more arms.

For teachers: any echinoderm of the class Asteroidea, characterised by a flattened body and radiating arms.

- The diver found a bright red asteroid clinging to the side of the coral reef.
- Marine biologists observed the asteroid using its tube feet to pry open the shell of a bivalve during the feeding cycle.

Usage: In modern general English, 'starfish' or 'sea star' is almost always preferred over 'asteroid'.

## Examples

- An asteroid hit the moon last night.
- Scientists track large asteroids to ensure none will collide with Earth in the coming decades.
- The discovery of a new asteroid belt between Mars and Jupiter reshaped our understanding of how the solar system formed billions of years ago.

---

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.