Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

tridacna

noun
tri·​dac·​na | \ trə̇ˈdaknə\

Definition of tridacna

1 capitalized : a genus of marine bivalves (family Tridacnidae) having no anterior adductor muscle and an equivalve shell the valves of which are very thick and heavy and strongly plicated at the margin — see giant clam
2 plural -s : any mollusk of the genus Tridacna : giant clam

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 tridacna

New Latin, from Latin, an oyster, from Greek tridaknos eaten at three bites, from tri- three + -daknos (from daknein to bite)

Keep scrolling for more

Learn More about tridacna

Statistics for tridacna

Look-up Popularity

Comments on tridacna

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

Show Comments  Hide Comments 

WORD OF THE DAY

kludge

Listen to the pronounciation of kludge

a haphazard or makeshift solution

Get Word of the Day daily email!

Test Your Vocabulary

Summer 2019 Words of the Day Quiz

  • a-bowl-of-peach-sorbet-with-cut-peaches-next-to-it
  • Which is a synonym of desideratum?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Word Winder's CrossWinder

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