1858, mistaken singular of aborigines (1540s; the correct singular is aboriginal), from Latin Aborigines "the first ancestors of the Romans; the first inhabitants" (especially of Latium), possibly a tribal name, or from ab origine, literally "from the beginning." Extended 1789 to natives of other countries which Europeans have colonized. Australian slang shortening Abo attested from 1922.
The earliest known inhabitants of a region. The term is most often associated with the native hunting and gathering population of Australia, who preceded the arrival of white settlers. (See hunting and gathering societies.)