What does "planetesimal" mean?

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

What is a synonym for "planetesimal"?

Common synonyms include: astral, astronomic, astronomical, astrophysical, galactic, heavenly.

adj, noun

adj, noun ·Uncommon ·Advanced level

Noun

1
Any of many small, solid astronomical objects that orbit a star and form protoplanets through mutual gravitational attraction.
2
one of many small solid celestial bodies thought to have existed at an early stage in the development of the solar system wordnet

Adjective

1
Being or relating to one of these astronomical objects. not-comparable
"a planetesimal body"

Formed from planet by analogy with infinitesimal.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.