planetary

American  

[plan-i-ter-ee] / ˈplæn ɪˌtɛr i /

adjective

1. of, relating to, or resembling a planet or the planets.

2. wandering; erratic.

3. terrestrial; global.

4. Machinery. noting or pertaining to an epicyclic gear train in which a sun gear is linked to one or more planet gears also engaging with an encircling ring gear.

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noun

1. Machinery. a planetary gear train.

planetary British  

/ ˈplænɪtərɪ, -trɪ /

adjective

1. of or relating to a planet

2. mundane; terrestrial

3. wandering or erratic

4. astrology under the influence of one of the planets

5. (of a gear, esp an epicyclic gear) having an axis that rotates around that of another gear

6. (of an electron) having an orbit around the nucleus of an atom

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noun

1. a train of planetary gears

Other Word Forms

• nonplanetary adjective

Etymology

Origin of planetary

From the Latin word planētārius, dating back to 1585–95. See planet, -ary

Example Sentences

Part of the museum’s expansive textile collection, Rosalena’s 27-foot-long tapestry is woven with hand-weaving patterns using satellite images the artist distorted from planetary terrains from Mars and Earth.

From The Wall Street Journal • Apr. 1, 2026

To Jef Caers, a professor of earth and planetary sciences at Stanford University who happens to be Belgian, the museum’s stance looks like “delay tactics.”

From The Wall Street Journal • Mar. 28, 2026

It was "grounding", she said, "to make that connection to our planetary home".

From BBC • Mar. 15, 2026

A violent planetary collision could easily generate that level of heat.

From Science Daily • Mar. 11, 2026

Aristarchus was the first person to hold that the Sun rather than the Earth is at the center of the planetary system, that all the planets go around the Sun rather than the Earth.

From "Cosmos" by Carl Sagan

Related Words

• global
• terrestrial