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

Another term for a certain kind of planetary alignment, planet parades are what happens when planets line up along the ecliptic in a straight line and appear to us on Earth to be marching across the night sky, according to NASA. — Eric Lagatta, USA Today, 10 July 2026

Even once in a while, from under the ocean floor, hot magma erupts through the gaps and then cools down to form new planetary crust. — Ameya Paleja, Interesting Engineering, 9 July 2026

But recent papers and presentations to the United Nations provide clues as to what the country has in mind for planetary defense. — Andrew Jones, Space.com, 9 July 2026

In 1993, a team led by the planetary scientist Carl Sagan tentatively concluded that there is life on Earth. — Quanta Magazine, 8 July 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