plural noun

: an order or other division of Choanichthyes including a number of fossil fishes known from the Devonian and later formations and three surviving genera, Neoceratodus, Protopterus, and Lepidosiren, comprising aberrant fishes that have overlapping cycloid scales and dermal fin rays, a largely cartilaginous skeleton with a persistent notochord, an autostylic skull, paired fins of the archipterygial type, gills covered by an operculum, and in addition a lung or pair of lungs communicating with the ventral side of the esophagus by a short tube

Word History


New Latin, from masculine plural of dipnous having two apertures for breathing

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!

Dictionary Entries Near Dipnoi

Cite this Entry

“Dipnoi.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Dipnoi. Accessed 12 Jun. 2024.

Love words? Need even more definitions?

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