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

While some of these instruments were shut off after the spacecraft finished their historic planetary flybys decades ago, others were turned off due to power requirements. — Elizabeth Howell, Space.com, 7 Aug. 2026

Rogue planets drift alone through interstellar space after either being ejected from their original planetary systems or forming independently without ever orbiting a star. — Kaif Shaikh, Interesting Engineering, 6 Aug. 2026

In it, Regina and planetary scientist Melissa Rice explore all things shooting stars. — Regina G. Barber, NPR, 5 Aug. 2026

The solar eclipse in Leo, for instance, could bring travel, publishing or legal developments your way, while Mercury’s conjunction with your lucky planetary ruler, Jupiter, amplifies your voice through teaching, media or a wider platform. — Valerie Mesa, PEOPLE, 1 Aug. 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
• apiary
• arbitrary
• aviary
• axillary
• bacillary
• beriberi
• bestiary
• breviary
• budgetary

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