variants: or less commonly allocthonous \ -​thənəs \

Definition of allochthonous

1a : of or relating to the rocks of an allochthon
b of coal : formed elsewhere than in situ and hence not autochthonous
c of limestone : composed largely of organic debris moved far from the place where the base organisms lived
2 biology : of foreign origin : introduced — compare autochthonous

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First Known Use of allochthonous

1888, in the meaning defined at sense 1a

History and Etymology for allochthonous

all- + -chthonous (as in autochthonous)

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The first known use of allochthonous was in 1888

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Cite this Entry

“Allochthonous.” Dictionary, Merriam-Webster, Accessed 4 Dec. 2020.

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