Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

Sirenia

plural noun
Si·​re·​nia | \ sīˈrēnēə\

Definition of Sirenia

: an order of large aquatic herbivorous mammals including the manatee, dugong, Steller's sea cow, and several fossil forms that have the tail horizontally flattened and expanded into a broad rounded or bilobed fin, the hind limbs rudimentary or wanting and the front ones paddle-shaped, and jaws with horny plates on the front part and usually numerous flat-crowned molar teeth

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 Sirenia

New Latin, from Latin siren + New Latin -ia

Keep scrolling for more

Learn More about Sirenia

Dictionary Entries near Sirenia

sireless

siren

siren call

Sirenia

sirenian

sirenic

Sirenidae

Statistics for Sirenia

Look-up Popularity

Comments on Sirenia

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

Show Comments  Hide Comments 

WORD OF THE DAY

redaction

Listen to the pronounciation of redaction

an act or instance of editing or removing

Get Word of the Day daily email!

Test Your Vocabulary

What's that Smell?! Quiz

  • wide eyed dog smelling rose
  • Someone who is hircine smells like a:
True or False

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

TAKE THE QUIZ
Syn City

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