Merriam-Webster Logo
SINCE 1828
Menu
×

An Encyclopædia Britannica Company

See What's Trending Now See More Trending Words

Mars

play
noun \ ˈmärz \

Definition of Mars

1 :the Roman god of war — compare ares
2 :the planet fourth in order from the sun and conspicuous for its red color — see Planets Table

See Mars defined for English-language learners

See Mars defined for kids

Explore M-W

alt-59c52d6ee2f72
Breathing Life Into 'Inspire'
video-title-words-of-the-year-1066
Words of the Year: 1066
young-plant-shoots
Merriam-Webster's New Words Quiz—Fall 2017 Edition!
alt-59c448f88ea38
Trending: Kim Jong Un: Trump a 'Dotard'

Origin and Etymology of mars

Latin Mart-, Mars

MARS Defined for English Language Learners

Mars

play
noun

Definition of Mars for English Language Learners

  • : the planet that is fourth in order from the sun

MARS Defined for Kids

Mars

play
noun \ ˈmärz \

Definition of Mars for Students

:the planet that is fourth in order of distance from the sun, is known for its redness, and has a diameter of about 4200 miles (6800 kilometers)

Learn More about mars

  1. See words that rhyme with Mars Spanish Central: Translation of Mars Nglish: Translation of Mars for Spanish speakers Britannica English: Translation of Mars for Arabic speakers Britannica.com: Encyclopedia article about Mars

Seen and Heard

What made you want to look up Mars? 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

toothsome

play

agreeable, attractive, or delicious

Get Word of the Day daily email!

TRENDING NOW

  1. dotage, dotard a state or period of senile decay

  2. otherwise "in other respects"

  3. federalism Graham says bill gives power to states

  4. bodega "Don’t mess with the beloved bodega."

  5. carceral Of, relating to, or suggesting a jail or prison

SEE ALL

BROWSE DICTIONARY

Mars

Test Your Vocabulary

Merriam-Webster's New Words Quiz—Fall 2017 Edition!

  • young-plant-shoots
  • Which of the following is a new sense of the word bunny?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Add Diction

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-59c52d6ee2f72
Breathing Life Into 'Inspire'

The word's origins are quite literal

alt-59c4207ecf106
Let's Talk 'Tea'

Spill it, sip it: just make it hot.

image1644821030
8 Words and Phrases from Boxing and Wrestling

Common terms that come from boxing and wrestling

alt-59c2960017c94
The Ambiguity of Pushing 'Up' and 'Back'

When you push a meeting, where does it go?

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

young-plant-shoots
Merriam-Webster's New Words Quiz—Fall 2017 Edition!

You're going to have to memorize the dictionary again.

Take the quiz
stylized-drawing-of-woman-pole-vaulting-across-gap-to-get-trophy
Challenging Vocabulary Quiz Returns!

No tricks, just difficult words.

Take the quiz
How Strong Is Your Vocabulary?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Take the quiz
Add Diction
Add Diction

Build a chain of words by adding one letter at a time.

Play the game