Tetrabranchia

plural noun

Tet·​ra·​bran·​chia
-aiŋ-
: a subclass or order of Cephalopoda including among existing forms only the genus Nautilus, differing from the remaining existing cephalopods in having four gills, four auricles to the heart, and a large chambered external shell, and including many extinct forms see ammonoidea , nautiloidea compare dibranchia

Word History

Etymology

New Latin, from tetra- + -branchia

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

  1. Expanded definitions
  2. Detailed etymologies
  3. Advanced search tools
  4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now

Dictionary Entries Near Tetrabranchia

Cite this Entry

“Tetrabranchia.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Tetrabranchia. Accessed 25 Dec. 2024.

Love words? Need even more definitions?

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