dol·​phin | \ ˈdäl-fən How to pronounce dolphin (audio) , ˈdȯl- \

Definition of dolphin

1a : any of various small marine toothed whales (family Delphinidae) with the snout more or less elongated into a beak and the neck vertebrae partially fused

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

b : any of several related chiefly freshwater toothed whales (as of the families Platanistidae and Iniidae) : river dolphin
3 capitalized : delphinus
4 : a spar or buoy for mooring boats also : a cluster of closely driven piles used as a fender for a dock or as a mooring or guide for boats

Illustration of dolphin

Illustration of dolphin

dolphin 1a

Examples of dolphin in a Sentence

Recent Examples on the Web The Centro de Interpratación Ambiental Natütama, run by a non-profit, offers a host of information on the pink dolphin and manatee species. Lucy Sherriff, CNN, 13 Aug. 2021 The nostril on the top of a whale or dolphin’s head. Los Angeles Times, 5 Aug. 2021 Penelope got warm with them under the blanket before joining a friend in sightseeing over the edge of the boat, which included some dolphin and seal appearances. Glenn Garner,, 25 July 2021 Andrew’s signature dance move is the dolphin and they both like brunch. Ali Barthwell, Vulture, 7 July 2021 Otherwise how could the hippopotamus have once been a dolphin? Cynthia Ozick, The New Yorker, 14 June 2021 The World Wildlife Fund’s logo is a giant panda; Oceana’s is a dolphin; the National Wildlife Federation’s mascot is Rick Raccoon in a ranger hat. Nathaniel Rich, WSJ, 30 Apr. 2021 Hans Jacob Hermansen, the former chairman of the Faroe Islands’ association behind the annual dolphin killings defended the practice last week. Washington Post, 19 Sep. 2021 Sea Shepherd Global hopes public outcry on an international level will spark an investigation into the recent Faroe Islands dolphin hunt. Vanessa Etienne,, 15 Sep. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'dolphin.' 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 dolphin

14th century, in the meaning defined at sense 1a(1)

History and Etymology for dolphin

Middle English delphyn, dolphyn, from Anglo-French delphin, alteration of Old French dalfin, from Medieval Latin dalfinus, alteration of Latin delphinus, from Greek delphin-, delphis; akin to Greek delphys womb, Sanskrit garbha

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

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Last Updated

10 Oct 2021

Cite this Entry

“Dolphin.” Dictionary, Merriam-Webster, Accessed 19 Oct. 2021.

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English Language Learners Definition of dolphin

: a small usually gray whale that has a pointed nose


dol·​phin | \ ˈdäl-fən How to pronounce dolphin (audio) , ˈdȯl- \

Kids Definition of dolphin

1 : a small whale with teeth and a long nose
2 : either of two large fish usually of warm seas that are often used for food

More from Merriam-Webster on dolphin

Nglish: Translation of dolphin for Spanish Speakers

Britannica English: Translation of dolphin for Arabic Speakers Encyclopedia article about dolphin


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