Mach·ae·rid·ia | \ ˌmakəˈridēə\
Definition of Machaeridia
: a small group of Ordovician and Devonian animal fossils that are wormlike and bilaterally symmetrical but enclosed by plates suggesting those of echinoderms, are considered structurally comparable to the dipleurula and ancestral to modern echinoderms, being then made a class of Echinodermata, or are regarded as aberrant barnacles and included among the Cirripedia
Keep scrolling for more
standardized text or formulaic language
Get Word of the Day daily email!
Love words? Need even more definitions?Merriam-Webster unabridged
Words at Play
Ask the Editors
- On Contractions of Multiple Words
- A Look at Uncommon Onomatopoeia
- Is Singular 'They' a Better Choice?
- Finance Words Quiz Take the quiz
- Namesakes Word Quiz Take the quiz
- Name That Thing Take the quiz
- SCRABBLE® Sprint Play the game