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

Winds reshape planetary models Earlier measurements also failed to account for Jupiter’s extreme winds, some of the most powerful in the solar system. —Neetika Walter, Interesting Engineering, 5 Feb. 2026

Think of this as the pessimistic, narrower option, where the greenhouse effect curtails the zone's inner edge and the loss of carbon dioxide from a planetary atmosphere marks its outer edge. —Keith Cooper, Space.com, 4 Feb. 2026

What's more, the rocky fragments could hold clues into how Mars developed into its current barren, rocky state, said study lead author Adrian Broz, a planetary scientist at Purdue University. —Eric Lagatta, USA Today, 4 Feb. 2026

This makes good sense on a planetary scale, or perhaps on an island with no imports/exports. —Alex Pavlak, Baltimore Sun, 1 Feb. 2026

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