plural noun
El·​y·​si·​idae | \ ˌeləˈsīəˌdē\

Definition of Elysiidae

: a family of slender creeping sea slugs with distinct head, tapering tail, auriculate tentacles, and lateral body folds functioning as fins when the animal swims

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 Elysiidae

New Latin, from Elysia, type genus + -idae

Keep scrolling for more

Comments on Elysiidae

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


concealment of treason or felony

Get Word of the Day daily email!

Test Your Vocabulary

The Exceptions Quiz III

  • one green toy robot amidst many red toy robots
  • Which of these words does not mean "nonsense"?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Bee Cubed

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

Love words? Need even more definitions?

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