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
cetaceous
si-ˈtā-shəs
adjective 
Example Sentences
Recent Examples on the Web Gray whale population histories during past eras, recreated by data from finds like the skeleton, suggest a possible, if tenuous, future for the cetacean in Atlantic waters. 
Brian Handwerk, Smithsonian Magazine, 19 July 2022 The cetacean was euthanized en route to a saltwater pool in Normand after being stuck at St.-Pierre-La-Garenne – a freshwater lock 45 miles northwest of Paris – starting on Aug. 2. Scott Gleeson, USA TODAY, 11 Aug. 2022 The vaquita, also known as the California harbor porpoise, is the smallest cetacean and makes its home in the northern part of the Gulf of California. Doug Johnson, Ars Technica, 6 May 2022 Assessing those impacts for the northernmost-ranging cetacean is important to formulating shipping, mining, and seismic guidelines and regulations as the region becomes a thoroughfare. Marguerite Holloway, The New Yorker, 31 Aug. 2021 Michael Packard was diving off the coast of Provincetown, Massachusetts, Friday, when the capital cetacean caught him unawares. Evan Simko-bednarski, CNN, 11 June 2021 Sperm whales are the only living cetacean that has a single blowhole asymmetrically situated on the left side of the crown of the head. al, 23 Nov. 2020 On the show The Boys, a speedboat smashes into a cetacean and the humans emerge unscathed. Rhett Allain, Wired, 14 Sep. 2020 As for the whale itself, experts are still unable to determine why the cetacean and its travel companions swam upriver in the first place. Gabrielle Chung, PEOPLE.com, 14 Sep. 2020 See More
Brian Handwerk, Smithsonian Magazine, 19 July 2022 The cetacean was euthanized en route to a saltwater pool in Normand after being stuck at St.-Pierre-La-Garenne – a freshwater lock 45 miles northwest of Paris – starting on Aug. 2. Scott Gleeson, USA TODAY, 11 Aug. 2022 The vaquita, also known as the California harbor porpoise, is the smallest cetacean and makes its home in the northern part of the Gulf of California. Doug Johnson, Ars Technica, 6 May 2022 Assessing those impacts for the northernmost-ranging cetacean is important to formulating shipping, mining, and seismic guidelines and regulations as the region becomes a thoroughfare. Marguerite Holloway, The New Yorker, 31 Aug. 2021 Michael Packard was diving off the coast of Provincetown, Massachusetts, Friday, when the capital cetacean caught him unawares. Evan Simko-bednarski, CNN, 11 June 2021 Sperm whales are the only living cetacean that has a single blowhole asymmetrically situated on the left side of the crown of the head. al, 23 Nov. 2020 On the show The Boys, a speedboat smashes into a cetacean and the humans emerge unscathed. Rhett Allain, Wired, 14 Sep. 2020 As for the whale itself, experts are still unable to determine why the cetacean and its travel companions swam upriver in the first place. Gabrielle Chung, PEOPLE.com, 14 Sep. 2020 See More Word History
Etymology
ultimately from Latin cetus whale, from Greek kētos
First Known Use
1840, in the meaning defined above