Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

agnathan

noun ag·na·than \ ˈag-nə-thən \

Definition of agnathan

plural agnathans
: jawless fish
  • Two jawless fishes (agnathans) are recognized in these fossils … based on differences in the shape and histology of their tubercles …
  • —Moya Meredith Smith,  Science,  18 Jan. 1991

There's more!

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!
Already a subscriber? Log in.

Origin and Etymology of agnathan

agnatha +1-an

Seen and Heard

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

show hide

Love words? Need even more definitions?

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

WORD OF THE DAY

pro rata

play

in proportion

Get Word of the Day daily email!

TRENDING NOW

  1. exculpatory 'tending or serving to exculpate'

  2. ideologue 'an often blindly partisan advocate or adherent of a particular ideology'

  3. socialism 'a way of organizing a society in which major industries are owned and controlled by the government'

  4. uphold 'to let stand'

  5. due process 'a course of formal proceedings (as judicial proceedings)'

SEE ALL

BROWSE DICTIONARY

agnathan

Test Your Vocabulary

Test Your Emoji Exceptionalism

  • test-your-emoji-exceptionalism-written-with-a-lot-of-emoji
  • What is this emoji intended to represent: 🤳
True or False

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

TAKE THE QUIZ
Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

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

Words at Play

Ask the Editors

Word Games