por·​poise | \ ˈpȯr-pəs How to pronounce porpoise (audio) \

Definition of porpoise

 (Entry 1 of 2)

1 : any of a family (Phocoenidae) of small gregarious toothed whales especially : a blunt-snouted usually dark gray whale (Phocoena phocoena) of the North Atlantic and North Pacific that typically ranges from 5 to 6 feet (1.5 to 1.8 meters) in length
2 : dolphin sense 1a(1) not used technically

Note: While not closely related, porpoises and dolphins share a physical resemblance that often leads to misidentification. Porpoises typically have flat, spade-shaped teeth, triangular dorsal fins, and shortened beaks with relatively small mouths while dolphins have cone-shaped teeth, curved dorsal fins, and elongated beaks with larger mouths.


porpoised; porpoising; porpoises

Definition of porpoise (Entry 2 of 2)

intransitive verb

1 : to leap or plunge like a porpoise penguins … porpoise out of the water— David Lewis
2 : to rise and fall repeatedly

Examples of porpoise in a Sentence

Recent Examples on the Web: Noun The government’s most recent analysis seems to accept the probability that the tiny porpoise species can never return to its original range of habitat. Wendy Fry, San Diego Union-Tribune, "Mexico considers reducing protections for vaquita porpoise in Gulf of California," 16 Mar. 2021 Aerial surveys for harbor porpoises, which began in 1986, allowed researchers to identify and track four distinct porpoise populations off California’s coast as gill netting bans rolled out over the following decade. Lindsey Mcginnis, The Christian Science Monitor, "Points of Progress: Mexico City cuts out plastic, and more," 11 Feb. 2021 Now, an international team of researchers, in collaboration with the Vertebrate Genomes Project, has used her living cells to generate the most complete high-quality genome sequence of any dolphin, porpoise or whale. Carolyn Cowan, Smithsonian Magazine, "Vaquita Genome Offers Hope for Species’ Survival," 9 Nov. 2020 George co-published a paper on harbor porpoise sightings near Point Barrow in 1993, along with author Robert Suydam. Jenna Kunze, Anchorage Daily News, "Harbor porpoise bycatch near Point Barrow contributes to larger study on Bering Sea population," 3 Sep. 2020 Search for minke whales, humpback whales, dolphins, and porpoises diving through the waves, and learn about the incredible diversity of sea life in Iceland’s waters. National Geographic, "Iceland Family Journey: Geysers, Glaciers, and Fjords," 17 June 2019 The nonprofit also responds to calls about deceased seals, whales, dolphins, porpoises and sea turtles. Laura Klairmont, CNN, "When Maine's seals are in trouble, she gets the call," 5 Mar. 2020 While other marine reptiles such as porpoise-like ichthyosaurs and long-necked plesiosaurs had the evolutionary flexibility to expand into deeper ocean environments, hyper-specialized thalattosaurs like Gunakadeit may have struggled to follow suit. Katherine J. Wu, Smithsonian Magazine, "215-Million-Year-Old, Sharp-Nosed Sea Creature Was Among the Last of Its Kind," 5 Mar. 2020 Dubbed the unicorn of the sea due to their long, spiraled tooth, narwhals are a beloved Arctic animal that, like other porpoise species, can be spotted swimming in groups of dozens or even hundreds of animals. National Geographic, "Penguins don't live at the South Pole, and more polar myths debunked," 3 Feb. 2020 Recent Examples on the Web: Verb Calvin stepped up to the glass, watching Fiona porpoise around Hippo Cove with her mother, Bibi. Mallorie Sullivan, Cincinnati.com, "Like Fiona, he was born prematurely. Their meeting will melt your heart.," 20 Feb. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'porpoise.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of porpoise


14th century, in the meaning defined at sense 1


1909, in the meaning defined at sense 1

History and Etymology for porpoise


Middle English porpoys, from Anglo-French porpeis, from Medieval Latin porcopiscis, from Latin porcus pig + piscis fish — more at farrow, fish

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Time Traveler for porpoise

Time Traveler

The first known use of porpoise was in the 14th century

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Statistics for porpoise

Last Updated

29 Mar 2021

Cite this Entry

“Porpoise.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/porpoise. Accessed 20 Apr. 2021.

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More Definitions for porpoise



English Language Learners Definition of porpoise

: a small usually gray and white whale that has a rounded nose


por·​poise | \ ˈpȯr-pəs How to pronounce porpoise (audio) \

Kids Definition of porpoise

1 : a small whale with teeth that resembles a dolphin but has a blunt rounded snout

More from Merriam-Webster on porpoise

Nglish: Translation of porpoise for Spanish Speakers

Britannica.com: Encyclopedia article about porpoise

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