planetary gear.

1. A gear that rotates around a central gear as part of an epicyclic arrangement.

2. An arrangement of gears in which planet gears turn around a central sun gear.

Use it for

Words that belong together

• a planetary gear
• planetary gear motion

On the page

The planetary gear moved around the central gear in the cutaway.

They found damage on one planetary gear beneath the cover.

Usage notes

Primary category: sci-fi. Forms: Singular planetary gear; plural planetary gears. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings.