pinion.

1. A relatively small toothed gear that engages another gear or a rack.

2. A bird’s wing or its flight-bearing feathers in a literary usage.

3. To restrain someone’s arms, or clip or bind a bird’s wing to prevent flight.

Use it for

Words that belong together

• a drive pinion
• rack and pinion

On the page

The drive pinion engaged the rack as the door moved.

A broken pinion tooth interrupted the motion.

Usage notes

Primary category: sci-fi. Forms: Singular pinion; plural pinions. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings. Third-person singular: pinions.