cetacean
noun
ce·ta·cean
si-ˈtā-shən 
: any of an order (Cetacea) of aquatic mostly marine mammals that includes the whales, dolphins, porpoises, and related forms and that have a torpedo-shaped nearly hairless body, paddle-shaped forelimbs but no hind limbs, one or two nares opening externally at the top of the head, and a horizontally flattened tail used for locomotion
cetacean
adjective
Examples of cetacean in a Sentence
Recent Examples on the Web
According to a May publication in the Journal of Wildlife Diseases, researchers at UH Mānoa and the College of Tropical Agriculture and Human Resilience found Brucella infections in seven species of cetaceans from 2000 to 2024, with striped dolphins showing the highest prevalence.
—
Thomas Westerholm, MSNBC Newsweek, 25 June 2025
Their analysis revealed that 71 of the tools were made from the bones of cetaceans, the group of marine mammals that includes whales, dolphins and porpoises.
—Sarah Kuta, Smithsonian Magazine, 28 May 2025
Smaller shark species such as requiem sharks and ancestors of today’s cetaceans, dolphins and whales, were next.
—David Bressan, Forbes.com, 26 May 2025
Such evidence could support the view that incessant loud noise amounts to torture or cruel treatment towards cetaceans, in turn galvanizing support for a new right to be free from such harm.
—David Gruber, Time, 24 Apr. 2025
See All Example Sentences for cetacean
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.
Thomas Westerholm, MSNBC Newsweek, 25 June 2025
Their analysis revealed that 71 of the tools were made from the bones of cetaceans, the group of marine mammals that includes whales, dolphins and porpoises.
—Sarah Kuta, Smithsonian Magazine, 28 May 2025
Smaller shark species such as requiem sharks and ancestors of today’s cetaceans, dolphins and whales, were next.
—David Bressan, Forbes.com, 26 May 2025
Such evidence could support the view that incessant loud noise amounts to torture or cruel treatment towards cetaceans, in turn galvanizing support for a new right to be free from such harm.
—David Gruber, Time, 24 Apr. 2025
See All Example Sentences for cetacean
Cite this Entry
“Cetacean.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cetacean. Accessed 19 Jul. 2025.
Copy CitationKids Definition
cetacean
noun
ce·ta·cean
si-ˈtā-shən
: any of an order of aquatic mammals (as a whale, dolphin, or porpoise)
cetacean
adjective
Love words? Need even more definitions?
Merriam-Webster unabridged
Share