from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Originating where found; indigenous: autochthonous rocks; an autochthonous people; autochthonous folktales. See Synonyms at native.
- adj. Biology Originating or formed in the place where found: an autochthonous blood clot.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Native to the place where found; indigenous.
- adj. Originating where found.
- adj. Buried in place, especially of a fossil preserved in its life position without disturbance or disarticulation.
from The Century Dictionary and Cyclopedia
- Pertaining to autochthons; indigenous; sprung from the soil; aboriginal.
- In pathology, not extraneous; originating at the place where found.
- In petrol., noting rocks which have originated in situ, such as peat, rock-salt, and stalagmitic limestone; also applied to constituent minerals of rocks which have crystallized in the place they now occupy. Autochthonous materials are contrasted with the mechanically derived particles of clastic rocks.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. of rocks, deposits, etc.; found where they and their constituents were formed
- adj. originating where it is found
Literally, "native to the soil"; from autochthon + -ous. (Wiktionary)