Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

Archaeocyatha

plural noun Ar·chaeo·cy·a·tha
See What's Trending Now See More Trending Words

Definition of Archaeocyatha

in some classifications
: a phylum of extinct animals of uncertain systematic relations represented by fossils of the genus Archaeocyathus

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 archaeocyatha

New Latin, from Archaeocyathus

Seen and Heard

What made you want to look up Archaeocyatha? 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

arrogate

play

to seize or ascribe

Get Word of the Day daily email!

TRENDING NOW

  1. embolization 'the process by which a blood vessel or organ is obstructed by a material mass'

  2. oleaginous 'marked by an offensively ingratiating manner or quality'

  3. pansexual 'sexual desire or attraction...not limited to a particular gender identity or sexual orientation'

  4. symbiote 'an organism living in symbiosis'

  5. charlatan 'faker or fraud'

SEE ALL

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

image250923223
Noun + Verb Insult Generator

A collection of obscure put-downs

alt-5b0834b915e3f
'Judicial' v. 'Judicious': We'll Settle The Case

A judgment call

alt-5b06e60511014
'Deprived' vs. 'Depraved'

Nobody wants to be either.

alt-5b05d8545c817
'Folksonomy': Let’s Get Organized

Tag the way you want to tag.

Ask the Editors

video-ghost-words
Ghost Word

The story of an imaginary word that managed to sneak past our editors and enter the dictionary.

image1760257654
2017 Word of the Year: Behind the Scenes

How we chose 'feminism'

video-literally
Literally

How to use a word that (literally) drives some people nuts.

video-his-or-her
Is Singular 'They' a Better Choice?

The awkward case of 'his or her'

Word Games

spring-flowers
May 2018 Words of the Day Quiz

We’re already at the end of May?!

Take the quiz
image1676440788
Words Used by Nabokov Quiz

How familiar are you with Nabokov’s unfamiliar vocabulary?

Take the quiz
How Strong Is Your Vocabulary?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Take the quiz
Syn City
Syn City

Build a city of skyscrapers—one synonym at a time.

Play the game