Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

Sirius

noun Sir·i·us \ ˈsir-ē-əs \
See What's Trending Now See More Trending Words

Definition of Sirius

: a star of the constellation Canis Major that is the brightest star in the heavens — called also Dog Star

See Sirius defined for kids

Origin and Etymology of sirius

Middle English, from Latin, from Greek Seirios

Other Astronomy Terms

gibbous, nadir, nebulous, penumbra, retrograde, sidereal, syzygy, wane, wax, zenith

Learn More about sirius

  1. See words that rhyme with Sirius

Seen and Heard

What made you want to look up Sirius? 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

slew

play

a large number

Get Word of the Day daily email!

TRENDING NOW

  1. symbiote 'an organism living in symbiosis'

  2. charlatan 'faker or fraud'

  3. lowlife 'a person of low moral character'

  4. kakistocracy 'government by the worst people'

  5. slimeball 'a morally repulsive or odious person'

SEE ALL

BROWSE DICTIONARY

Sirius

Test Your Vocabulary

Odd Habits and Quirks Quiz

  • image1926873504
  • Which of the following best describes an easily irritated person?
True or False

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

TAKE THE QUIZ
Dictionary Devil

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

image278155226
All the Hits

8 obscure words for bodily harm

alt-5adf93a49b0b2
The Fossil Encased in "Case In Point"

"In point" only lives in this phrase.

alt-5adf5d017e6bf
‘Sleight’ or ‘Slight’ of Hand?

Watch closely and be amazed.

alt-5ade0f1ca7a0c
'Complement' vs. 'Compliment'

The distinction is clear (now).

Ask the Editors

image1760257654
2017 Word of the Year: Behind the Scenes

How we chose 'feminism'

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'

video-literally
Literally

How to use a word that (literally) drives some people nuts.

video-his-or-her
Is Singular 'They' a Better Choice?

The awkward case of 'his or her'

Word Games

image1926873504
Odd Habits and Quirks Quiz

Test your knowledge of strange human behaviors.

Take the quiz
cats-on-impossible-timber
More Confusing Words—Quiz

How many of these commonly confused words do you know?

Take the quiz
True or False
True or False?

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

Take the quiz
Dictionary Devil
Dictionary Devil

The dictionary has been scrambled—can you put it back together?

Play the game