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

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

Examples of planetary in a Sentence

a positively planetary new shopping development

Recent Examples on the Web

According to a new study by a team of researchers led by University of Chicago planetary scientist Edwin Kite, a new clue may provide not only a part of the answer, but indicates that Mars may have been doomed to its current fate from the beginning. —New Atlas, 12 July 2025

In July, the U.S. Senate appropriations committee advanced a bill that would reject the 47% science cut, instead funding NASA at $24.9 billion and preserving key Earth and planetary missions. —Daisy Dobrijevic, Space.com, 11 July 2025

In the 1990s, a field team led by planetary geologist Eugene Shoemaker arrived atop the Island in the Sky District of Canyonlands National Park in Utah. —Mike Bezemek, Smithsonian Magazine, 10 July 2025

Yet at least one planetary scientist refuses to be hamstrung by focusing on the funding hole in the Martian sample return donut. —Bruce Dorminey, Forbes.com, 10 July 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