SINCE 1828

An Encyclopædia Britannica Company

Alioth

noun Al·i·oth \ ˈa-lē-ˌäth \

Definition of Alioth

astronomy

:a variable star of the first magnitude that is seen in the handle of the Big Dipper and is one of the two brightest stars in that constellation

Alioth, otherwise known as HD 112185, is a variable star with a very well-defined period, its brightness changing by 0.03 magnitude every 5.09 days.
—Shireen Gonzaga, Astronomy, December 1991

— called also Epsilon Ursae Majoris

There's more!

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!

First Known Use of alioth

1704

Seen and Heard

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

show

WORD OF THE DAY

euphony

play

pleasing or sweet sound

BROWSE DICTIONARY

alinotum

alintatao

Alioth

Ali Paşa

alipata

Test Your Vocabulary

Forms of Government Quiz

A gerontocracy is rule by:

How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ

SCRABBLE® Sprint

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

TAKE THE QUIZ

Words at Play

alt-59e50f5a357b4

'Spox' May Go On The Record

From newsroom lingo to the mainstream

alt-59e506c5c02ae

C'mon, Of Course 'Myriad' Is a Noun

For a myriad of reasons

alt-59e12097b419d

'Gamut' and 'Gambit' (and 'Gauntlet' Too)

Know when to use (or run) each.

17 English Words that Come From Japanese

Some borrowed words don't get returned

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'

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

knupfer-painting-solon-before-croesus

Forms of Government Quiz

Name that government! Or something like that.

Take the quiz

rembrandt-painting-a-young-scholar-and-his-tutor

Original Meanings Quiz

A quiz for the pedantic and those annoyed by them!

Take the quiz

How Strong Is Your Vocabulary?

How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Take the quiz

SCRABBLE® Sprint

SCRABBLE® Sprint

SCRABBLE® fans, sharpen your skills!

Play the game