os·​te·​ich·​thy·​an | \ ˌä-stē-ˈik-thē-ən How to pronounce osteichthyan (audio) \
variants: or less commonly osteichthian
plural osteichthyans also osteichthians

Definition of osteichthyan

: 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

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!

Other Words from osteichthyan

osteichthyan or less commonly osteichthian adjective
osteichthyan fishes

First Known Use of osteichthyan

1967, in the meaning defined above

Learn More About osteichthyan

Time Traveler for osteichthyan

Time Traveler

The first known use of osteichthyan was in 1967

See more words from the same year

Dictionary Entries Near osteichthyan




See More Nearby Entries 

Statistics for osteichthyan

Cite this Entry

“Osteichthyan.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/osteichthyan. Accessed 29 Nov. 2021.

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


Test Your Vocabulary

Difficult Spelling Words Quiz

  • alphabet pasta spelling help
  • Which is the correct spelling?
True or False

Test your knowledge - and maybe learn something along the way.

Love words? Need even more definitions?

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