Word.ws English Dictionary

mastodon

Syllables: mas·to·don/ˈmæs.tə.dɒn/US/ˈmæs.tə.dɑn/

mastodon noun: extinct elephant-like mammal of the genus †Mammut that flourished worldwide from Miocene through Pleistocene times; differs from elephants and mammoths in the form of the molar teeth.

mastodon: extinct elephant-like mammal of the genus †Mammut that flourished worldwide from Miocene through...
Image: John Collins Warren, Public domain, via Wikimedia Commons

Noun (1)

mastodon (plural mastodons)

  1. Extinct elephant-like mammal of the genus †Mammut that flourished worldwide from Miocene through Pleistocene times; differs from elephants and mammoths in the form of the molar teeth.
    • When, exactly, Europeans first stumbled upon the bones of an American mastodon is unclear. An isolated molar unearthed in a field in upstate New York was sent off to London in 1705; it was labeled the “tooth of a Giant”.2014, Elizabeth Kolbert, chapter 2, in The Sixth Extinction: An Unnatural History, Henry Holt and Company
    Synonyms:
    incognitum
  2. (figuratively) Anything awkwardly large or unwieldy.
    • The battery is dying, and Natalia's iPhone charger doesn't fit my mastodon of a phone anyway.2017, Nina Laurin, Girl Last Seen
    • Nor does it work for governance: the policy has become such a mastodon that we can't adapt it quickly enough to different regions or different circumstances.2020, Finn Laursen, The Development of the EU as a Sea-Policy Actor

Proper noun capitalized: Mastodon

Mastodon

  1. (social media) A decentralized microblogging platform, part of the Fediverse.
    • However, the underlying design of platforms within [The Free Network] such as Mastodon, Diaspora and others ... opens the door to security and harassment problems.2020, Kevin Veale, Gaming the Dynamics of Online Harassment, Springer International Publishing, →ISBN, page 113
    • Since Musk bought the bird app last month, users are looking for ways to access Mastodon, the open source microblogging platform that isn’t quite Twitter but seems to be the closest thing to it, and they’re signing up for its many servers in droves.2022 November 9, Amanda Hoover, “Twitter Users Have Caused a Mastodon Meltdown”, in Wired, San Francisco, Calif.: Condé Nast Publications, →ISSN, →OCLC, archived from the original on 09 Nov 2022

Noun (2) capitalized: Mastodon

Mastodon (plural Mastodons)

  1. A nickname for both the 4-8-0 and (though erroneously) the 4-10-0 train configurations.

Synonyms of mastodon

Forms of mastodon

pluralmastodons
alternative formmastodont
pluralMastodons

Plural of mastodon: mastodons

Origin of mastodon

First attested 1813, from translingual Mastodon (1806), coined by French naturalist Georges Cuvier, from masto- (“breast”) + -odon (“tooth”), due to the mammilloid (“nipple-shaped”) projections on the crowns of the extinct mammal's molars.

See mastodon.

Words formed from mastodon

Questions about mastodon

What does mastodon mean?
Mastodon means extinct elephant-like mammal of the genus †Mammut that flourished worldwide from Miocene through Pleistocene times; differs from elephants and mammoths in the form of the molar teeth.
What part of speech is mastodon?
Mastodon can be a noun or a proper noun.
How do you pronounce mastodon?
Mastodon is pronounced /ˈmæs.tə.dɒn/ (UK).
What is the plural of mastodon?
The plural of mastodon is mastodons.

Words near mastodon in the dictionary

  1. mastocytoma
  2. mastocytomas
  3. mastocytomata
  4. mastocytoses
  5. mastocytosis
  6. mastodon
  7. mastodonian
  8. Mastodonians
  9. mastodonic
  10. mastodons
  11. mastodonsaur

Source and license

Adapted from Wiktionary: mastodon (page history and authors); Mastodon (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Pronunciation audio from Wikimedia Commons, each file under its own free license: LL-Q1860 (eng)-Vealhurl-mastodon.wav.

Cite this entry: “mastodon.” Word.ws, https://word.ws/mastodon. Based on Wiktionary, CC BY-SA 4.0.