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
And the tracking device attached to his dorsal fin is helping researchers uncover secrets about the elusive apex predator.
—Bill Kearney, Sun Sentinel, 22 Jan. 2026
Giles examined the fins and saddle patches (a swirly white marking behind the dorsal fin) to identify these whales as part of J-pod.
—Kelso Harper, Scientific American, 16 Dec. 2025
The most notable additions to the exterior are the air intake on the roof, the carbon-fiber dorsal fin, the enlarged rear wing, and a new hood.
—Viju Mathew, Robb Report, 17 Nov. 2025
Moctezuma’s pod was identified by the distinct markings on the orcas’ dorsal fins.
—Aamir Khollam, Interesting Engineering, 3 Nov. 2025
The baby whale was later identified with a deep gash near its dorsal fin.
—Moná Thomas, PEOPLE, 27 Oct. 2025
This fish, distinguished by its long whisker-like barbels and unique dorsal fin, was found in a small stream within a deep gorge.
—Real-Time News Team, Miami Herald, 26 Sep. 2025
There is nothing quite like the thrill of spotting a dorsal fin slicing through open water or watching a pod leap through the surf beside your boat.
—Alexandra Emanuelli, Southern Living, 18 Sep. 2025
That gives the wearer a look akin to the shark's infamously fearsome dorsal fin, along with plenty of extra thrust and speed.
—New Atlas, 8 Sep. 2025
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Bill Kearney, Sun Sentinel, 22 Jan. 2026
Giles examined the fins and saddle patches (a swirly white marking behind the dorsal fin) to identify these whales as part of J-pod.
—Kelso Harper, Scientific American, 16 Dec. 2025
The most notable additions to the exterior are the air intake on the roof, the carbon-fiber dorsal fin, the enlarged rear wing, and a new hood.
—Viju Mathew, Robb Report, 17 Nov. 2025
Moctezuma’s pod was identified by the distinct markings on the orcas’ dorsal fins.
—Aamir Khollam, Interesting Engineering, 3 Nov. 2025
The baby whale was later identified with a deep gash near its dorsal fin.
—Moná Thomas, PEOPLE, 27 Oct. 2025
This fish, distinguished by its long whisker-like barbels and unique dorsal fin, was found in a small stream within a deep gorge.
—Real-Time News Team, Miami Herald, 26 Sep. 2025
There is nothing quite like the thrill of spotting a dorsal fin slicing through open water or watching a pod leap through the surf beside your boat.
—Alexandra Emanuelli, Southern Living, 18 Sep. 2025
That gives the wearer a look akin to the shark's infamously fearsome dorsal fin, along with plenty of extra thrust and speed.
—New Atlas, 8 Sep. 2025
Cite this Entry
“Dorsal fin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dorsal%20fin. Accessed 2 Feb. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
