# rhea

/ˈɹiə/ (US) · /ɹˈiː/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/rhea
Updated: 2026-08-15

## Definition

a large, cold moon that orbits the planet Saturn. It is covered in ice and has many craters on its surface.

For teachers: the second-largest moon of Saturn, composed primarily of water ice with a rocky core. It is a geologically inactive body characterized by a heavily cratered surface and a thin atmosphere of oxygen and carbon dioxide.

## Examples

- Rhea is one of the many moons orbiting Saturn.
- Images from the Cassini spacecraft revealed that Rhea has a very thin atmosphere, which was a surprising discovery for a moon of its size.
- As the second-largest satellite of Saturn, Rhea maintains a synchronous rotation, meaning the same face is always directed toward the gas giant as it completes its orbital path.

## Usage notes

- When referring to the specific moon of Saturn, it is treated as a proper noun and capitalized.

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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.