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
Video footage posted by the group shows one of the orcas, distinguished by its tall dorsal fin, briefly breaching the choppy surface before slipping back below the waves.
—Brendan Rascius, Miami Herald, 6 May 2025
The species is the only one in the North Pacific Ocean without a dorsal fin, and the animals can grow as large as 10 feet long and weigh 250 pounds.
—Charlotte Phillipp, People.com, 28 Feb. 2025
The footage was retrieved when the buoyant camera tag popped off the shark’s dorsal fin and washed ashore at the Gulfstream Golf Club in Delray Beach, officials said.
—Mark Price, Miami Herald, 11 Apr. 2025
According to the outlet, a ping means the Smart Position and Temperature Transmitting (SPOT) tag attached to the shark’s dorsal fin remained above water for a brief period as the animal swam, transmitting a near-live location signal to the OCEARCH shark tracker.
—Taylor Ardrey, USA TODAY, 12 Feb. 2025
Both fish have two dorsal fins, but largemouths have a tell-tale break between the fins, while smallmouths have clearly connected dorsal fins.
—Derek Horner, Outdoor Life, 27 Feb. 2025
With a large, sail-like dorsal fin protruding from their backs and shimmery scales, these fish have a distinctive appearance.
—Sarah Kuta, Smithsonian Magazine, 6 Feb. 2025
Northern right whale dolphins are the only dolphin in the North Pacific Ocean to not have a dorsal fin and usually travel in packs of 100 to 200, according to the National Oceanic and Atmospheric Administration.
—Paloma Chavez, Sacramento Bee, 3 Mar. 2025
Another way to distinguish the two is by looking at their dorsal fins.
—Derek Horner, Outdoor Life, 27 Feb. 2025
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Brendan Rascius, Miami Herald, 6 May 2025
The species is the only one in the North Pacific Ocean without a dorsal fin, and the animals can grow as large as 10 feet long and weigh 250 pounds.
—Charlotte Phillipp, People.com, 28 Feb. 2025
The footage was retrieved when the buoyant camera tag popped off the shark’s dorsal fin and washed ashore at the Gulfstream Golf Club in Delray Beach, officials said.
—Mark Price, Miami Herald, 11 Apr. 2025
According to the outlet, a ping means the Smart Position and Temperature Transmitting (SPOT) tag attached to the shark’s dorsal fin remained above water for a brief period as the animal swam, transmitting a near-live location signal to the OCEARCH shark tracker.
—Taylor Ardrey, USA TODAY, 12 Feb. 2025
Both fish have two dorsal fins, but largemouths have a tell-tale break between the fins, while smallmouths have clearly connected dorsal fins.
—Derek Horner, Outdoor Life, 27 Feb. 2025
With a large, sail-like dorsal fin protruding from their backs and shimmery scales, these fish have a distinctive appearance.
—Sarah Kuta, Smithsonian Magazine, 6 Feb. 2025
Northern right whale dolphins are the only dolphin in the North Pacific Ocean to not have a dorsal fin and usually travel in packs of 100 to 200, according to the National Oceanic and Atmospheric Administration.
—Paloma Chavez, Sacramento Bee, 3 Mar. 2025
Another way to distinguish the two is by looking at their dorsal fins.
—Derek Horner, Outdoor Life, 27 Feb. 2025
Cite this Entry
“Dorsal fin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dorsal%20fin. Accessed 14 May. 2025.
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