Definition of cetacean
: 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
cetaceousplay \-shəs\ adjective
Recent Examples of cetacean from the Web
What sort of organism?: A cetacean related to today's baleen whales.
No other cetacean has the distinctive vertical crease seen on the foreheads of these dolphins, which have indistinguishable beaks, according to NOAA.
This cetacean is an anatomical bridge between more archaic forms like Basilosaurus and the profusion of baleen whales that followed.
Mexican scientist Gustavo Cardenas and Jennifer Trickey, a researcher with Scripps, are using the devices to track populations and behaviors of the elusive cetaceans.
Researchers have long guessed at why baleen whales—a group of cetaceans that includes humpback, minke, right whales and others—grew so big.
In the 25 years she's been observing orcas and other cetaceans in the bay, she's become familiar with how orcas interact with the region's other residents.
Not since the Yangtze River dolphin went extinct in 2006 in China has a cetacean gone over the brink.
The world’s smallest member of the cetacean grouping, which includes whales and dolphins, the vaquita was the most recent cetacean to be recognized by modern science.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cetacean.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Origin and Etymology of cetacean
ultimately from Latin cetus whale, from Greek kētos
First Known Use: 1835See Words from the same year
CETACEAN Defined for English Language Learners
Definition of cetacean for English Language Learners
: a mammal (such as a whale, dolphin, or porpoise) that lives in the ocean
Learn More about cetacean
Britannica.com: Encyclopedia article about cetacean
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