dolphin

American  

[dawl-fin, dol-] / ˈdɔl fɪn, ˈdɒl- /

noun

• dolphins
  plural

1. any of several chiefly marine, cetacean mammals of the family Delphinidae, having a fishlike body, numerous teeth, and the front of the head elongated into a beaklike projection.

2. Also called dolphinfish, mahimahi.  Also called pompano dolphin.  either of two large, slender fishes, Coryphaena hippurus or C. equisetis, of warm and temperate seas.

3. Nautical.

   1. a pile, cluster of piles, or buoy to which a vessel may be moored in open water.

   2. a cluster of piles used as a fender, as at the entrance to a dock.

   3. a pudding fender at the nose of a tugboat or on the side of a vessel.

4. Astronomy. Dolphin, the constellation Delphinus.

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dolphin British  

/ ˈdɒlfɪn /

noun

1. any of various marine cetacean mammals of the family Delphinidae , esp Delphinus delphis, that are typically smaller than whales and larger than porpoises and have a beaklike snout

2. any freshwater cetacean of the family Platanistidae, inhabiting rivers of North and South America and S Asia. They are smaller than marine dolphins and have a longer narrower snout

3. Also called: dorado.  either of two large marine percoid fishes, Coryphaena hippurus or C. equisetis, that resemble the cetacean dolphins and have an iridescent coloration

4. nautical a post or buoy for mooring a vessel

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Other Word Forms

Noun Inflected Forms

• dolphins
  plural

Etymology

Origin of dolphin

First recorded in 1300–50; Middle English dolphyn, from Old French daulphin, from Old Provençal dalfin, from unattested Vulgar Latin dalfīnus, Latin delphīnus, from Greek delphī́n

Explanation

Dolphins are smart, sociable aquatic mammals that live in every ocean on the planet. Scientists aren't sure why they do it, but dolphins are known for leaping above the surface of the water as they swim. Dolphins are one of the most commonly recognized and beloved sea creatures, in part because they are gregarious and friendly. Their playful nature and intelligence have brought dolphins into close contact with humans, not always to their benefit. Scientists have learned that dolphins live longer, happier lives when they're not in captivity, so you're less likely to see dolphins at an aquarium than in the past. Dolphins are mammals, giving birth to live babies, which may explain the Greek root of dolphin, delphys, meaning "womb."

Example Sentences

See Examples For:

dolphin dolphins

Except for the part where they pluck and prune themselves into the hairlessness of a dolphin; “Love is Blind’s” Zack Goytowski and “Love Island’s” Zach Georgiou both cop to shaving their legs.

From The Wall Street Journal ● Aug. 22, 2026

Israel’s Army Radio reported that Hamas claims to have captured an Israeli spy dolphin, equipped with surveillance gear, off the coast of Gaza.

From The Wall Street Journal ● May 14, 2026

He wouldn’t say if the U.S. had dolphin assets in the water.

From Barron's ● May 6, 2026

A group of kayakers say they had an "incredible surprise" when a curious dolphin swam beside them as they paddled under the Forth Rail Bridge.

From BBC ● Oct. 25, 2025

The dolphin was swimming alongside me, not too close but way too close for comfort.

From "Adrift" by Paul Griffin

It is also a staple for whales, dolphins and seabirds.

From Barron's ● Aug. 18, 2026

Head out with Sado Emotion in search of the Sado’s resident bottlenose dolphins, with a cruise along the Arrábida coast.

From The Wall Street Journal ● Aug. 17, 2026

I picked him up at Los Angeles International Airport and took him straight to Zuma Beach for a picnic, where we watched dolphins jumping in the waves while the seagulls stole our potato chips.

From Los Angeles Times ● Jun. 26, 2026

In contrast, fishermen working with dolphins may interpret different dolphin behaviors as cues for when to cast their nets, and those signals can vary from one region to another.

From Science Daily ● Jun. 20, 2026

And the painted dolphins on your sister’s wall cannot plot deadly schemes.

From "Challenger Deep" by Neal Shusterman