1
: a part of a sail taken in or let out in regulating size
2
: reduction in sail area by reefing
reefed; reefing; reefs
1
: to reduce the area of (a sail) by rolling or folding a portion
2
: to lower or bring inboard (a spar) wholly or partially
: to reduce a sail by taking in a reef
1
a
: a chain of rocks or coral or a ridge of sand at or near the surface of water compare atoll, barrier reef
b
: a hazardous obstruction
Examples of reef in a Sentence
Recent Examples on the Web
Gordon G. Chang, Newsweek, 31 Oct. 2024
And a zillion other colorful, oddball fish went about their business on the reef.
—Betsy Andrews, Travel + Leisure, 30 Oct. 2024
The development of artificial reefs, for example, is one initiative that spotlights Dubai’s holistic approach to protecting the marine ecosystem.
—Dubai Tourism Contributor, Forbes, 22 Oct. 2024
Widespread coral bleaching results in sick reefs that are more vulnerable to illness, water pollution and other threats.
—Andrew Freedman, Axios, 21 Oct. 2024
See all Example Sentences for reef 
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Noun
In response, countries including New Zealand, the United Kingdom, Germany, and France pledged nearly $30 million in new contributions to the U.N. Coral Reef Fund, which aims to gather up to $3 billion by 2030 to support reef conservation initiatives.
—Gordon G. Chang, Newsweek, 31 Oct. 2024
And a zillion other colorful, oddball fish went about their business on the reef.
—Betsy Andrews, Travel + Leisure, 30 Oct. 2024
The development of artificial reefs, for example, is one initiative that spotlights Dubai’s holistic approach to protecting the marine ecosystem.
—Dubai Tourism Contributor, Forbes, 22 Oct. 2024
Widespread coral bleaching results in sick reefs that are more vulnerable to illness, water pollution and other threats.
—Andrew Freedman, Axios, 21 Oct. 2024
See all Example Sentences for reef
Dictionary Entries Near reef
Cite this Entry
“Reef.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/reef. Accessed 22 Nov. 2024.
Copy CitationKids Definition
reef
1 of 3 noun1
: a part of a sail taken in or let out in regulating size
2
: the reduction in sail area made by reefing
reef
2 of 3 verb
: to reduce the area of (a sail) by rolling or folding a portion
reef
3 of 3 noun
: a chain of rocks or coral or a ridge of sand at or near the surface of water
Etymology
Noun
Middle English riff "reef of a sail"; of Norse origin
Noun
from Dutch rif "reef of rocks or sand"; of Scandinavian origin
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