mas·to·don | \ˈmas-tə-ˌdän, -dən\

Definition of mastodon 

1 : any of various extinct mammals (genus Mammut synonym Mastodon) of the elephant family existing from the Miocene through the Pleistocene that are distinguished from the related mammoths chiefly by molar teeth with cone-shaped cusps

2 : one that is unusually large

Keep scrolling for more

Other Words from mastodon

mastodonic \ˌmas-tə-ˈdä-nik \ adjective
mastodont \ˈmas-tə-ˌdänt \ adjective or noun

Examples of mastodon in a Sentence

mom-and-pop stores just can't compete with these mastodons of retailing

Recent Examples on the Web

On a much smaller scale, the city’s residents fumed—Hosack prominent among them—when a mastodon fossil excavated in the Hudson Valley was spirited across state lines for the glory of that rival city, Philadelphia. Penelope Rowlands, WSJ, "‘American Eden’ Review: The Ambitious Dr. Hosack," 1 June 2018 Mammoths and mastodons, for example, likely had a two-year gestation period, akin to modern elephants, and would have typically produced just one offspring at a time. Jason G. Goldman, Scientific American, "In 200 Years Cows May Be the Biggest Land Mammals on the Planet," 20 Apr. 2018 Boys dig up prehistoric mastodon fossil in Mississippi. Fox News, "FOX NEWS FIRST: Trump mulls sending National Guard to U.S.-Mexico border; Suspected shooter had feud with YouTube," 4 Apr. 2018 Two months later, a work crew uncovered a massive mastodon skull buried in the ground. Steve Lord, Aurora Beacon-News, "Mastodon model approved for Aurora exhibit at Phillips Park," 3 Mar. 2018 At the on-site archaeological museum of the same name, bone up on the 12,000-year-old history of Illinois River Valley denizens, from Ice Age nomads who hunted huge mastodons to tribal groups that left Illinois in the 19th century. Lori Rackl,, "Bicentennial bucket list," 19 Mar. 2018 The final stop on her mini-tour deals with fossils like the mastodon, which dates to the most recent Ice Age that ended around 10,000 years ago in Wisconsin. Brian E. Clark, Milwaukee Journal Sentinel, "A mastodon and a meteor older than Earth are highlights of the UW Geology Museum," 9 Mar. 2018 Aldermen approved a contract with Taylor Studios, in Rantoul, for $89,289 for the mastodon. Steve Lord, Aurora Beacon-News, "Mastodon model approved for Aurora exhibit at Phillips Park," 3 Mar. 2018 The Aurora City Council is set to approve the final part of the Mastodon Island work to be done this summer — the actual interactive mastodon model. Steve Lord, Aurora Beacon-News, "Aurora set to buy interactive mastodon for Phillips Park display," 24 Feb. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mastodon.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of mastodon

1811, in the meaning defined at sense 1

History and Etymology for mastodon

New Latin mastodont-, mastodon, from Greek mastos + odont-, odōn, odous tooth — more at tooth

Keep scrolling for more

Learn More about mastodon

Statistics for mastodon

Look-up Popularity

Time Traveler for mastodon

The first known use of mastodon was in 1811

See more words from the same year

Keep scrolling for more

More Definitions for mastodon



English Language Learners Definition of mastodon

: a type of animal that was related to the mammoth and that lived in ancient times

Keep scrolling for more

Comments on mastodon

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


to reject or criticize sharply

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

  • the-triumph-of-venus-by-alessandro-magnasco
  • Boreal comes from the name of the ancient Greek god of which wind?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Word Winder's CrossWinder

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


Love words? Need even more definitions?

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