plural noun Ar·thro·di·ra

Definition of Arthrodira

  1. :  a group of Devonian fishes forming a subclass of Placodermi or especially formerly an order of Ostracodermi or a separate class and having the forepart of the body protected by bony plates and with an imperfectly ossified internal skeleton — see coccosteidae, dinichthys


adjective or noun


noun, plural



\-¦dīrəs\ adjective

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.

Join MWU now and get access to America’s largest dictionary, with:

  • 300,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Origin and Etymology of arthrodira

New Latin, from arthr- + -dira (from Greek deirē neck); akin to Latvian grīva mouth of a river, Old Slavic griva mane, Sanskrit grīva neck, Latin vorare to devour — more at voracious

First Known Use: 1891

Seen and Heard

What made you want to look up Arthrodira? Please tell us where you read or heard it (including the quote, if possible).


to criticize severely

Get Word of the Day daily email!