planetary

adjective

plan·​e·​tary ˈpla-nə-ˌter-ē 

1

a

: of, relating to, being, or resembling a planet

b

: erratic, wandering

c

: having a motion like that of a planet

planetary electrons

d

: immense

the scope of this project has reached planetary proportions

2

a

: of, relating to, or belonging to the earth : terrestrial

b

: global, worldwide

planetary politics

3

: having or consisting of an epicyclic train of gear wheels

Synonyms of planetary

• vast
• giant
• huge
• gigantic
• astronomical
• tremendous
• enormous
• massive
• colossal
• mammoth
• monumental
• bumper
• immense
• cosmic
• galactic
• titanic
• mountainous
• oceanic
• monster
• grand
• monstrous

Examples of planetary in a Sentence

a positively planetary new shopping development

Recent Examples on the Web

That's why, even though the comet poses no threat to Earth, the world's astronomers and space agencies are racing to study planetary material that formed from another star. —Eric Lagatta, USA Today, 3 Nov. 2025

The most famous, prominent planetary nebulae are all suspected to contain binary companions. —Big Think, 3 Nov. 2025

And while Musk’s companies have unmatched reach in space infrastructure, scaling an SRM system to planetary levels is another story. —Neetika Walter, Interesting Engineering, 3 Nov. 2025

An ancient comet that entered our solar system this summer is offering a rare opportunity to learn more about distant planetary systems far beyond the reach of any spacecraft, researchers say. —NPR, 30 Oct. 2025

Word History

First Known Use

1607, in the meaning defined at sense 1a

Phrases Containing planetary

• planetary nebula
• planetary science

Rhymes for planetary

• accessary
• adversary
• ancillary
• arbitrary
• aviary
• axillary
• beriberi
• breviary
• budgetary
• capillary
• catenary
• cautionary

Kids Definition

planetary

adjective

plan·​e·​tary ˈplan-ə-ˌter-ē 

1

a

: of or relating to a planet

b

: having a motion like that of a planet

planetary electrons of the atomic nucleus

2

: worldwide, global

a matter of planetary concern