reef.

1. A ridge of rock, coral, or other material near a water surface.

2. To secure part of a sail so less surface catches the wind.

Use it for

Words that belong together

• coral reef
• offshore reef

On the page

Waves broke over the offshore reef.

Usage notes

Primary category: setting / environment. Forms: Singular reef; plural reefs. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings. Established modern English lexical item. No separate regional spelling or grammatical inflection entry. Commonness: moderately common. Third-person singular: reefs.