cetacean

noun

ce·​ta·​cean si-ˈtā-shən How to pronounce cetacean (audio)
: 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
cetaceous
si-ˈtā-shəs How to pronounce cetacean (audio)
adjective

Examples of cetacean 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.
Whale Watching The waters around Channel Islands National Park teem with wildlife all year long, giving the chance to spot 27 different species of cetaceans, including humpback and gray whales, dolphins, porpoises, and orcas. — Cu Fleshman, Travel + Leisure, 27 Aug. 2026 For more than 600 years, the community has relied on hunting whales and other cetaceans for food, with the meat shared throughout the village. — Cecilia Rodriguez, Forbes.com, 23 Aug. 2026 The three cetaceans who came to San Diego via a Qatar Airways Boeing 777 cargo plane are among 30 whales that had been at risk of being euthanized if they could not be relocated from Marineland. — Lori Weisberg, San Diego Union-Tribune, 22 Aug. 2026 Officials advise sailors not to use deterrent measures that could kill, injure or disturb the cetaceans. — Stepheny Price, FOXNews.com, 18 Aug. 2026 See All Example Sentences for cetacean

Word History

Etymology

ultimately from Latin cetus whale, from Greek kētos

First Known Use

1840, in the meaning defined above

Time Traveler
The first known use of cetacean was in 1840

Rhymes for cetacean

See All Rhymes for cetacean

Browse Nearby Words

Cetacea
cetacean
cetaceous
See all Nearby Words

Cite this Entry

“Cetacean.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/cetacean. Accessed 1 Sep. 2026.

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Kids Definition

cetacean

noun
ce·​ta·​cean si-ˈtā-shən How to pronounce cetacean (audio)
: any of an order of aquatic mammals (as a whale, dolphin, or porpoise)
cetacean adjective

More from Merriam-Webster on cetacean

Britannica.com: Encyclopedia article about cetacean

Last Updated: - Updated example sentences
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