Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

blue whale

noun

Definition of blue whale

  1. :  a very large baleen whale (Balaenoptera musculus synonym Sibbaldus musculus) that may reach a weight of 150 tons (136 metric tons) and a length of 100 feet (30 meters) and is generally considered the largest living animal

See blue whale defined for English-language learners

See blue whale defined for kids

People Are Reading

image1358596246
Words About Word Play
emoji-the-quiz
The Emoji Quiz
alt-5978a79b75e17
Trending: 'Transgender' Americans Face New Restrictions
alt-597a00ef4b9d7
'Motif' vs 'Leitmotif'

Illustration of blue whale

First Known Use of blue whale

1851

BLUE WHALE Defined for English Language Learners

blue whale

noun

Definition of blue whale for English Language Learners

  • : a very large bluish-gray whale

BLUE WHALE Defined for Kids

blue whale

noun

Definition of blue whale for Students

  1. :  a very large whale that is generally considered the largest living animal

Learn More about blue whale

  1. Britannica.com: Encyclopedia article about blue whale

Seen and Heard

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

show hide

Love words? Need even more definitions?

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

WORD OF THE DAY

fester

play

to become worse as time passes

Get Word of the Day daily email!

TRENDING NOW

  1. transgender Trump reverses military policy allowing transgender people to serve

  2. beleaguer 'Being subjected to constant or repeated trouble or harassment'

  3. scaramouch A new White House communications director

  4. non sequitur “It does not follow”

  5. admiral's mast A massive search ends with an 'admiral's mast'.

SEE ALL

BROWSE DICTIONARY

blue whale

Test Your Vocabulary

The Emoji Quiz

  • emoji-the-quiz
  • What phase of the moon is this: 🌖 ?
True or False

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

TAKE THE QUIZ
Citation

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

alt-597a00ef4b9d7
'Motif' vs 'Leitmotif'

A pattern emerges.

alt-5978b44edfb13
Our (Almost) Final Word on 'Penultimate'

The ultimate guide to using penultimate.

alt-5978cb55e8ba5
The Grammatical History of 'Awaken'/'Awoken'/'Awakened'

Or you can just go back to bed.

alt-59775cb5d7779
Words We're Watching: 'Aquafaba'

Don't dump out the bean water just yet...

Ask the Editors

video-title-words-of-the-year-1066
Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

payday
How Often Is 'Biweekly'?

Don't get us started on 'bimonthly'

video-irregardless-grammar-peeve-blend-of-the-synonyms-irrespective-and-regardless
Irregardless

It is in fact a real word (but that doesn't mean you should use it).

video-moose-goose-weird-plurals
Weird Plurals

One goose, two geese. One moose, two... moose. What's up with that?

Word Games

emoji-the-quiz
The Emoji Quiz

Think you’re an emoji 👓 expert? Let’s see 🤔

Take the quiz
image941935269
A Game of Thrones Word Quiz

In the Game of Thrones quiz, you learn some new vocabulary. (It’s quite safe, really. You will not die.)

Take the quiz
True or False
True or False?

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

Take the quiz
Citation
Citation

Do you know the person or title these quotes describe?

Play the game