Source : Webster's Revised Unabridged Dictionary (1913)

Abortion \A*bor"tion\ ([.a]*b[^o]r"sh[u^]n), n. [L. abortio, fr.
   aboriri. See {Abort}.]
   1. The act of giving premature birth; particularly, the
      expulsion of the human fetus prematurely, or before it is
      capable of sustaining life; miscarriage.

   Note: It is sometimes used for the offense of procuring a
         premature delivery, but strictly the early delivery is
         the abortion, ``causing or procuring abortion'' is the
         full name of the offense. --Abbott.

Source : WordNet®

abortion
     n 1: termination of pregnancy
     2: failure of a plan [syn: {miscarriage}]