Cetacea

plural noun
Ce·​ta·​cea | \ sēˈtāshēə \

Definition of Cetacea

: an order of completely aquatic mostly marine eutherian mammals consisting of the whales, dolphins, porpoises, and related forms, all having a very large head, a tapering body like a fish and nearly devoid of hair, forelimbs like paddles, no hind limbs, a tail ending in a broad horizontal fin, a large brain, a complex stomach of four or more chambers, and two mammae posterior in position

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

History and Etymology for Cetacea

New Latin, from neuter plural of cetaceus cetaceous

Keep scrolling for more

Learn More About Cetacea

Dictionary Entries Near Cetacea

CETA

Cetacea

cetacean

See More Nearby Entries 

Statistics for Cetacea

Cite this Entry

“Cetacea.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Cetacea. Accessed 29 Jul. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

WORD OF THE DAY

Test Your Vocabulary

Farm Idioms Quiz

  • cow coming home
  • What does 'poke' refer to in the expression 'pig in a poke'?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
Typeshift

Anagram puzzles meet word search.

TAKE THE QUIZ
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!