Risso's dolphin

noun

Ris·​so's dolphin ˈri-sōz- 

: a dolphin (Grampus griseus) widely distributed in temperate and tropical seas that has a blunt snout, a rounded forehead, and teeth in the lower jaw only

Risso's dolphins, which have small mouths and large foreheads, are deep ocean divers that stay offshore and are rarely seen close to shore.

—Peter Fimrite

called also grampus

Examples of Risso's dolphin in a Sentence

Recent Examples on the Web

Other species include the Atlantic spotted dolphin and the Risso's dolphin. —Dinah Voyles Pulver, USA TODAY, 19 Mar. 2025

Video footage captured by Capt. Evan Brodsky of Monterey Bay Whale Watch on Friday shows the Risso's dolphins, also called gray dolphins, breaching and gliding in Carmel Bay, just off the central coast of California. —Saman Shafiq, USA TODAY, 30 Jan. 2025

The sighting was rare: Risso's dolphins typically travel in groups of only 10 to 30 animals, according to the National Oceanic and Atmospheric Administration. —CBS News, 29 Jan. 2025

Beyond the orcas and sea lions, the whale watch also recorded seeing 50 Risso's dolphins, a type of blunt-headed dolphin common along the California coast. —Kerry Breen, CBS News, 14 Dec. 2023

Word History

Etymology

after Giuseppe Antonio (Joseph Antoine) Risso †1845 naturalist born in Nice

Note: Risso contributed a description and drawing of the dolphin, apparently never published on their own, to the French zoologist Georges Cuvier (1769-1832), who briefly described and illustrated the dolphin on the basis of Risso's account in "Rapport … sur divers Cétacées pris sur les côtes de France …," Annales du Muséum d'historie naturelle, tome 19 (1812), pp. 12-13 and plate 1 (under the taxonomic name Delphinus griseus). A later synonym was Delphinus rissoanus (1827), on which the current common name may be based.

First Known Use

1870, in the meaning defined above