# planetesimal

> English word · Noun

## Definitions
1. Any of many small, solid astronomical objects that orbit a star and form protoplanets through mutual gravitational attraction.

## Etymology
Formed from planet by analogy with infinitesimal.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/planetesimal