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

The image was captured near the northern end of the Eumenides Dorsum mountains, part of the huge, dusty Medusae Fossae Formation, and not far (in planetary terms) from the towering volcanic province of Tharsis. —Kenna Hughes-Castleberry, Space.com, 20 Jan. 2026

Mars talk, Musk, and what is not happening There is no evidence that SpaceX or any major space company is pursuing Greenland as a formal test site for Mars colonization technology or planetary settlement systems. —Kaif Shaikh, Interesting Engineering, 19 Jan. 2026

Then on January 23rd, Mars, your planetary ruler, enters Aquarius for six weeks, motivating you to take action around creating more stability or emotional safety in your personal life. —Dossé-Via Trenou, Refinery29, 18 Jan. 2026

Why do planetary conjunctions occur? —Jenna Prestininzi, Freep.com, 16 Jan. 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