Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

deltidium

noun
del·​tid·​i·​um
plural deltidia\ -​dēə \

Definition of deltidium

1 : a plate partly or wholly closing the delthyrium of certain brachiopods

— called also pseudodeltidium

2 : a pair of plates not homologous with the pseudodeltidium that performs the same function in other brachiopods

— called also deltidial plates

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!

History and Etymology for deltidium

New Latin, from Greek delta + New Latin -idium

Keep scrolling for more

Learn More about deltidium

Share deltidium

Statistics for deltidium

Look-up Popularity

Comments on deltidium

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

Show Comments  Hide Comments 

WORD OF THE DAY

decoct

Listen to the pronounciation of decoct

to boil down or concentrate

Get Word of the Day daily email!

Test Your Vocabulary

Original Meanings Quiz

  • rembrandt-painting-a-young-scholar-and-his-tutor
  • Which of the following is the earliest known sense of the word awe?
True or False

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

TAKE THE QUIZ
SCRABBLE® Sprint

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