allochthon

noun

al·​loch·​thon

əˈläkthən,

aˈ-,

-ˌthän

variants or allochthone

-ˌthōn

plural -s

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

Word History

Etymology

back-formation from allochthonous

First Known Use

1931, in the meaning defined above

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!