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
Jake Parks, Discover Magazine, 3 Feb. 2025
The reef areas where C. cyclolites live are typically high-energy zones with strong waves and significant competition for space.
—Katie Hunt, CNN, 1 Feb. 2025
The seas, too, saw changes in reef composition, precipitous drops in plankton and the disappearance of whale-sized ichthyosaurs while their smaller relatives lived on during the same time.
—Riley Black, Smithsonian Magazine, 22 Jan. 2025
Explore Underwater At Navarre Beach Marine Sanctuary For excellent snorkeling, head to this marine sanctuary, which has three different artificial reef habitats about 100 yards from the shores of Navarre Beach.
—Lisa Cericola, Southern Living, 17 Jan. 2025
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Noun
The war of corals: patterns, drivers and implications of changing coral competitive performances across reef environments
animal behavior
animals
water
ocean
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—Jake Parks, Discover Magazine, 3 Feb. 2025
The reef areas where C. cyclolites live are typically high-energy zones with strong waves and significant competition for space.
—Katie Hunt, CNN, 1 Feb. 2025
The seas, too, saw changes in reef composition, precipitous drops in plankton and the disappearance of whale-sized ichthyosaurs while their smaller relatives lived on during the same time.
—Riley Black, Smithsonian Magazine, 22 Jan. 2025
Explore Underwater At Navarre Beach Marine Sanctuary For excellent snorkeling, head to this marine sanctuary, which has three different artificial reef habitats about 100 yards from the shores of Navarre Beach.
—Lisa Cericola, Southern Living, 17 Jan. 2025
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 12 Feb. 2025.
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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