origin (n.)

"person, animal, or plant that has been in a country or region from earliest times," 1858, mistaken singular of aborigines (1540s; aboriginal is considered the correct singular in English), from Latin aborigines "the first inhabitants," especially of Latium, hence "the first ancestors of the Romans." This is possibly a tribal name, or from or made to conform to the Latin phrase ab origine, which means literally "from the beginning."

This is from ab "off, away from" (see ab-) + ablative of origo "a rise, commencement, beginning, source; descent, lineage, birth," from stem of oriri "arise, rise; be born, be descended, receive life" (see origin).

It was extended by 1789 to natives of other countries which Europeans had colonized, especially "aboriginal inhabitant of Australia," with capital A-. The Australian English slang shortening Abo is attested from 1922 as a noun, by 1906 as an adjective.

1570s, "to miscarry in giving birth," from Latin abortus, past participle of aboriri "to miscarry, be aborted, fail, disappear, pass away," a compound word used in Latin for deaths, miscarriages, sunsets, etc., which according to OED is from ab, here as "amiss" (see ab-), + stem of oriri "appear, be born, arise," from PIE *heri- "to rise" (see origin). [Watkins, contra de Vaan, etc., derives the second element from a suffixed form of PIE root *er- (1) "move, set in motion."]

The English word is attested from 1610s as "to deliberately terminate" anything (intransitive), but especially a pregnancy in a human or animal. Intransitive use in aeronautics and space-flight is by 1946. Transitive meaning "to cause (a woman) to miscarry" is recorded by 1916; with the fetus or pregnancy as the object of the action, by 1966. Related: Aborted; aborting. The Latin verb for "produce an abortion" was abigo, literally "to drive away."