Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

Sirius

play
noun Sir·i·us \ˈsir-ē-əs\

Definition of Sirius

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

See Sirius defined for kids

Read the Latest from M-W

alt-597a2ef226ea8
Are You Craving 'Ice Tea' or 'Iced Tea'?
image2136071978
Tech-y Terms Are Older Than You Think
video-title-words-of-the-year-1066
Words of the Year: 1066
alt-597a99e699d07
July 2017 Words of the Day Quiz

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 Britannica.com: Encyclopedia article about 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

melee

play

a confused struggle

Get Word of the Day daily email!

TRENDING NOW

  1. implode How does implode differ from explode?

  2. ballistic What makes a missile ballistic?

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

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

  5. scaramouch A new White House communications director

SEE ALL

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-597a2ef226ea8
Are You Craving 'Ice Tea' or 'Iced Tea'?

When tea is cold and refreshing, is it 'ice tea' or 'iced tea'?

image2136071978
9 Surprising Word Histories of Computer Terms

People have been blogging since the 18th century.

alt-597a00ef4b9d7
'Motif' vs 'Leitmotif'

A pattern emerges.

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

The ultimate guide to using penultimate.

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

alt-597a99e699d07
July 2017 Words of the Day Quiz

Test your knowledge.

Take the quiz
emoji-the-quiz
The Emoji Quiz

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

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