Aw-to-ch-th-AHN-ihc (soft "th" as in "thistle").

Another form of the word autochthonous- and the form, at least, that Philip K. Dick preferred.

It means native, or aboriginal- when a thing exists in the place it arose.

The Greek chthon means "earth", so there is a "on native soil" connotation. The English chthonic means "relating to the underworld", so there may be some confusion.