Adjective

(-)

Native to the place where found; indigenous.

* 1889 , Justin Winsor, Narrative and Critical History of America , Vol. I, page 375:

Two of the most celebrated of the evolutionists reject the autochthonous view, for Darwin's Descent of Man'' and Haeckel's ''Hist. of Creation consider the American man an emigrant from the old world, whatever way the race may have developed

* {{quote-book, year= 1983

, year_published= , author= (Isaac Asimov) , by= , title= (The Robots of Dawn) , url= , original= , chapter= 22 , section= , isbn= 0-553-29949-2 , edition= , publisher= Bantam Books , location= , editor= , volume= , page= 116 , passage= Only human beings could live on this world and know that they were not autochthonous but had stemmed from Earthmen—and yet did the Spacers really know it or did they simply put it out of their mind? }}

(biology, medicine) Originating where found; found where it originates.

* 1983 , Journal of the Medical Society of New Jersey , volume 80, page 538:

When, in 1858, Joseph Lister amputated the right leg of a six-year-old girl suffering from gangrene, he noted that the autochthonous blood clot extended down the anterior tibial artery as far as the commencement of the gangrene.

(geology) Buried in place, especially of a fossil preserved in its life position without disturbance or disarticulation.

* 1992 , Anna K. Behrensmeyer, et al., Terrestrial Ecosystems Through Time , page 83:

Death and burial may be simultaneous, resulting in a preserved snapshot of an autochthonous assemblage that may be compared directly with present day ecosystems.

Adjective

(en-adj)

Having lasted from a remote period; having been of long duration; of great age; very old.

* {{quote-book, year=1963, author=(Margery Allingham)

, title=(The China Governess) , chapter=Foreword citation , passage=‘I understand that the district was considered a sort of sanctuary,’ the Chief was saying. ‘An Alsatia like the ancient one behind the Strand, or the Saffron Hill before the First World War. […]’}}

Existent or occurring in time long past, usually in remote ages; belonging to or associated with antiquity; old, as opposed to modern.

* {{quote-book, year=2006, author=(Edwin Black), title=Internal Combustion

, chapter=2 citation , passage=Buried within the Mediterranean littoral are some seventy to ninety million tons of slag from ancient smelting, about a third of it concentrated in Iberia. This ceaseless industrial fueling caused the deforestation of an estimated fifty to seventy million acres of woodlands.}}

* {{quote-magazine, year=2013, month=July-August, author=(Henry Petroski)

, title= Geothermal Energy , volume=101, issue=4, magazine=(American Scientist) , passage=Energy has seldom been found where we need it when we want it. Ancient nomads, wishing to ward off the evening chill and enjoy a meal around a campfire, had to collect wood and then spend time and effort coaxing the heat of friction out from between sticks to kindle a flame. With more settled people, animals were harnessed to capstans or caged in treadmills to turn grist into meal.}}

(label) Relating to antiquity as a primarily European historical period; the time before the Middle Ages.

(obsolete) Experienced; versed.

* Berners

Though [he] was the youngest brother, yet he was the most ancient in the business of the realm.

(obsolete) Former; sometime.

* Alexander Pope

They mourned their ancient leader lost.