dorsal fin
noun
plural dorsal fins
: a flat thin body part that projects from the back of many fish (such as trout, barracuda, and sharks) and some marine mammals (such as dolphins)
Porpoises have a more triangular dorsal fin while a dolphin's dorsal fin is more curved.—
Naomi Corrigan and Dave Himelfield
Naomi Corrigan and Dave HimelfieldThis member of the perch family has two dorsal fins and a large mouth outfitted with sharp teeth …—Matt Markey
Matt MarkeyExamples of dorsal fin in a Sentence
Recent Examples on the Web
Kikfin says the dorsal fin further improves mobility, helping quickly switch directions by simply turning their head.
—New Atlas, 8 Sep. 2025
The order was withdrawn a week later, but had scientists never tagged the shark’s dorsal fin, it likely wouldn’t have been targeted by this precrime unit.
—Ross Andersen, The Atlantic, 7 Sep. 2025
Sharks are often imagined cruising just beneath the waves, dorsal fin protruding from the dark, ocean waters to alert people of their incoming doom.
—Melissa Cristina Márquez, Forbes.com, 1 Sep. 2025
The video shows the shark's dorsal fin cutting across the water before the giant fish drifts along the side of the kayak, its skin visible just below the surface.
—Soo Kim, MSNBC Newsweek, 29 Aug. 2025
It was tagged below the dorsal fin, something Lambert is familiar with.
—Jon Chapman, Miami Herald, 27 Aug. 2025
Researchers are able to identify Old Thom based on his very distinct dorsal fin.
—Rick Sobey, Boston Herald, 12 Aug. 2025
Sticking Variety Remora adhesive disks are an evolutionary adaptation of the fish’s first dorsal fin, the one that in other species sits on top of the body, just behind the head and gill covers.
—Jacek Krywko, ArsTechnica, 9 Aug. 2025
For a ping to register, Contender's dorsal fin must break water and an Argos satellite must be nearby to record the shark's location.
—Stepheny Price, FOXNews.com, 23 July 2025
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New Atlas, 8 Sep. 2025
The order was withdrawn a week later, but had scientists never tagged the shark’s dorsal fin, it likely wouldn’t have been targeted by this precrime unit.
—Ross Andersen, The Atlantic, 7 Sep. 2025
Sharks are often imagined cruising just beneath the waves, dorsal fin protruding from the dark, ocean waters to alert people of their incoming doom.
—Melissa Cristina Márquez, Forbes.com, 1 Sep. 2025
The video shows the shark's dorsal fin cutting across the water before the giant fish drifts along the side of the kayak, its skin visible just below the surface.
—Soo Kim, MSNBC Newsweek, 29 Aug. 2025
It was tagged below the dorsal fin, something Lambert is familiar with.
—Jon Chapman, Miami Herald, 27 Aug. 2025
Researchers are able to identify Old Thom based on his very distinct dorsal fin.
—Rick Sobey, Boston Herald, 12 Aug. 2025
Sticking Variety Remora adhesive disks are an evolutionary adaptation of the fish’s first dorsal fin, the one that in other species sits on top of the body, just behind the head and gill covers.
—Jacek Krywko, ArsTechnica, 9 Aug. 2025
For a ping to register, Contender's dorsal fin must break water and an Argos satellite must be nearby to record the shark's location.
—Stepheny Price, FOXNews.com, 23 July 2025
Cite this Entry
“Dorsal fin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dorsal%20fin. Accessed 10 Sep. 2025.
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