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

• astronomical
• astronomic
• Brobdingnagian
• bumper
• colossal
• cosmic
• cosmical
• cyclopean
• elephantine
• enormous
• galactic
• gargantuan
• giant
• gigantesque
• gigantic
• grand
• herculean
• heroic
• heroical
• Himalayan
• huge
• humongous
• humungous
• immense
• jumbo
• king-size
• king-sized
• leviathan
• mammoth
• massive
• mega
• mighty
• monster
• monstrous
• monumental
• mountainous
• oceanic
• pharaonic
• prodigious
• super
• super-duper
• supersize
• supersized
• titanic
• tremendous
• vast
• vasty
• walloping
• whacking
• whopping

Examples of planetary in a Sentence

a positively planetary new shopping development

Recent Examples on the Web

In September 2022, NASA’s Double Asteroid Redirection Test — the first demo mission to test planetary defense technology — impacted asteroid Dimorphos and successfully changed its orbit. —Jamie Carter, Forbes.com, 18 June 2025

The planetary nebulae — which, despite the name, have nothing to do with planets — could bear fruit in the future, as they can be used by astronomers to make distance measurements. —Robert Lea, Space.com, 18 June 2025

The planetary boundary for ocean acidification is defined as a 20% decline from the pre-industrial aragonite saturation state, a measure of ocean water's ability to support calcifying organisms such as corals and shellfish. —Thomas Westerholm, MSNBC Newsweek, 16 June 2025

The opportunity cost —in terms of sustainable growth, prosperity, and planetary stability—is immense. —Sturla Henriksen, Time, 5 June 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