os·​te·​ich·​thy·​an ˌä-stē-ˈik-thē-ən How to pronounce osteichthyan (audio)
variants or less commonly osteichthian
plural osteichthyans also osteichthians
: a fish of the class Osteichthyes : a bony fish
Extant jawed vertebrates, or gnathostomes, fall into two major monophyletic groups, namely chondrichthyans (cartilaginous fishes) and osteichthyans (bony fishes and tetrapods).Hector Botella et al., Nature, 2 Aug. 2007
osteichthyan adjective
or less commonly osteichthian
osteichthyan fishes

Word History

First Known Use

1967, in the meaning defined above

Time Traveler
The first known use of osteichthyan was in 1967

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 osteichthyan

Cite this Entry

“Osteichthyan.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/osteichthyan. Accessed 23 Jul. 2024.

Love words? Need even more definitions?

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