Antecedent, a.
Etymology: [L. antecedens, -entis, p. pr. of antecedere: cf. F. antécédent.]
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.
1 other Webster entry under this spelling
Antecedent, n.
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.
Shades of meaning
Fernald has no entry of its own for antecedent; he lists it under cause, precedent, previous.
Where he writes about it:
An antecedent simply precedes a result, with or without any agency in producing it; as, Monday is the invariable antecedent of Tuesday, but not the cause of it. — from cause
The direct antonym of cause is effect, while that of antecedent is consequent. — from cause
Antecedent may denote simple priority in time, implying no direct connection between that which goes before and that which follows; as, the striking of one clock may be always antecedent to the striking of another with no causal connection between them. — from previous
Antecedent and previous may refer to that which goes or happens at any distance in advance, preceding is limited to that which is immediately or next before; an antecedent event may have happened at any time before; the preceding transaction is the one completed just before the one with which it is compared; a previous statement or chapter may be in any part of the book that has gone before; the preceding statement or chapter comes next before without an interval. — from previous