Source : Webster's Revised Unabridged Dictionary (1913)

Antecedent \An`te*ced"ent\, a. [L. antecedens, -entis, p. pr. of
   antecedere: cf. F. ant['e]c['e]dent.]
   1. Going before in time; prior; anterior; preceding; as, an
      event antecedent to the Deluge; an antecedent cause.

   2. Presumptive; as, an antecedent improbability.

   Syn: Prior; previous; foregoing.

Antecedent \An`te*ced"ent\, n. [Cf. F. ant['e]c['e]dent.]
   1. That which goes before in time; that which precedes.
      --South.

            The Homeric mythology, as well as the Homeric
            language, has surely its antecedents. --Max Miller.

   2. One who precedes or goes in front. [Obs.]

            My antecedent, or my gentleman usher. --Massinger.

   3. pl. The earlier events of one's life; previous principles,
      conduct, course, history. --J. H. Newman.

            If the troops . . . prove worthy of their
            antecedents, the victory is surely ours. --Gen. G.
                                                  McClellan.

   4. (Gram.) The noun to which a relative refers; as, in the
      sentence ``Solomon was the prince who built the temple,''
      prince is the antecedent of who.

   5. (Logic)
      (a) The first or conditional part of a hypothetical
          proposition; as, If the earth is fixed, the sun must
          move.
      (b) The first of the two propositions which constitute an
          enthymeme or contracted syllogism; as, Every man is
          mortal; therefore the king must die.

   6. (Math.) The first of the two terms of a ratio; the first
      or third of the four terms of a proportion. In the ratio
      a:b, a is the antecedent, and b the consequent.

Source : WordNet®

antecedent
     adj : preceding in time or order [syn: {preceding}] [ant: {subsequent}]

antecedent
     n 1: someone from whom you are descended (but usually more remote
          than a grandparent) [syn: {ancestor}, {ascendant}, {ascendent},
           {root}] [ant: {descendant}]
     2: a preceding occurrence or cause or event
     3: anything that precedes something similar in time;
        "phrenology was an antecedent of modern neuroscience"
        [syn: {forerunner}]
     4: the referent of an anaphor; a phrase or clause that is
        referred to by an anaphoric pronoun