abortion (n.) Look up abortion at Dictionary.com
1540s, originally of both deliberate and unintended miscarriages; from Latin abortionem (nominative abortio) "miscarriage; abortion," noun of action from past participle stem of aboriri (see abortive).

Earlier noun in English was simple abort (early 15c.) "miscarriage." In 19c. some effort was made to distinguish abortion "expulsion of the fetus between 6 weeks and 6 months" from miscarriage (the same within 6 weeks of conception) and premature labor (delivery after 6 months but before due time). The deliberate miscarriage was criminal abortion. This broke down late 19c. as abortion came to be used principally for intentional miscarriages, probably via phrases such as procure an abortion.

Foeticide (n.) appears 1823 as a forensic medical term for deliberate premature fatal expulsion of the fetus; also compare prolicide. Another 19c. medical term for it was embryoctony, from Latinized form of Greek kteinein "to destroy." Abortion was a taboo word for much of early 20c., disguised in print as criminal operation (U.S.) or illegal operation (U.K.), and replaced by miscarriage in film versions of novels.