al·​loch·​thon | \ əˈläkthən, aˈ-, -ˌthän \
variants: or allochthone \ -​ˌthōn \
plural -s

Definition of allochthon

: an overthrust block of rocks that have been moved along a fault for a great distance from their place of origin

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 allochthon

1931, in the meaning defined above

History and Etymology for allochthon

back-formation from allochthonous

Keep scrolling for more

Learn More about allochthon

Time Traveler for allochthon

Time Traveler

The first known use of allochthon was in 1931

See more words from the same year

Statistics for allochthon

Cite this Entry

“Allochthon.” The Dictionary, Merriam-Webster Inc., Accessed 5 December 2019.

Comments on allochthon

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


to accept, comply, or submit

Get Word of the Day daily email!

Test Your Vocabulary

Semantic Drift Quiz

  • a twisty river
  • Which of the following was once a synonym for fun?
Spell It

Can you spell these 10 commonly misspelled words?

Syn City

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!