dolphin

noun

dol·​phin ˈdäl-fən How to pronounce dolphin (audio)
ˈdȯl-
1
a
: 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
2
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
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.
Lost or abandoned underwater fishing nets continue to trap everything in their path, from fish to turtles and dolphins, and harm delicate ecosystems. Claire Poole, Forbes.com, 30 Mar. 2025 The dolphins scattered and the men returned empty-handed. Prianka Srinivasan Matthew Abbott, New York Times, 26 Mar. 2025 At least 50 dolphins have been found poisoned and stranded on beaches, though domoic acid ingestion is typically a death sentence for them. Ryan Fonseca, Los Angeles Times, 25 Mar. 2025 After the SpaceX capsule splashed down in the Atlantic Ocean, they were greeted by a pod of dolphins swimming nearby. Alex Knapp, Forbes, 21 Mar. 2025 See All Example Sentences for dolphin

Word History

Etymology

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

First Known Use

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

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

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Cite this Entry

“Dolphin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dolphin. Accessed 3 Apr. 2025.

Kids Definition

dolphin

noun
dol·​phin ˈdäl-fən How to pronounce dolphin (audio)
ˈdȯl-
1
a
: any of various small whales with teeth and a long nose
2
: either of two active saltwater food fishes noted for their brilliant coloring

More from Merriam-Webster on dolphin

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