antecedent

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Going before; preceding.
• noun One that precedes another.
• noun A preceding occurrence, cause, or event. synonym: cause.
• noun The important events and occurrences in one's early life.
• noun One's ancestors.
• noun Grammar The word, phrase, or clause that determines what a pronoun refers to, as the children in The teacher asked the children where they were going.
• noun Mathematics The first term of a ratio.
• noun Logic The conditional member of a hypothetical proposition.

from The Century Dictionary.

• Being before in time, place, rank, or logical order; prior; anterior; as, an event antecedent to the deluge.
• noun One who or that which goes before in time or place.
• noun In grammar: The noun to which a relative, pronoun refers: as, Solomon was the prince who built the temple, where the word prince is the antecedent of who. Formerly, the noun to which a following pronoun refers, and whose repetition is avoided by the use of the pronoun.
• noun In logic: That member of a conditional proposition of the form, “If A is, then B is,” which states, as a hypothesis, the condition of the truth of what is expressed in the other member, termed the consequent: in the proposition given the antecedent is “if A is.”
• noun The premise of a consequence, or syllogism in the first figure with the major premise suppressed.
• noun An event upon which another event follows.
• noun In mathematics, the first of two terms of a ratio, or that which is compared with the other. Thus, if the ratio is that of 2 to 3, or of a to b, 2 or a is the antecedent.
• noun In music, a passage proposed to be answered as the subject of a fugue.
• noun plural The earlier events or circumstances of one's life; one's origin, previous course, associations, conduct, or avowed principles.
• In physical geography, noting rivers or streams which have persisted in their courses in spite of an uplift of the land: thus the Meuse is an antecedent river, because it has persisted in its course by cutting a deep gorge through the uplifted area of the Ardennes.

from the GNU version of the Collaborative International Dictionary of English.

• noun That which goes before in time; that which precedes.
• noun obsolete One who precedes or goes in front.
• noun The earlier events of one's life; previous principles, conduct, course, history.
• noun (Gram.) The noun to which a relative refers.
• noun The first or conditional part of a hypothetical proposition; as, If the earth is fixed, the sun must move.
• noun The first of the two propositions which constitute an enthymeme or contracted syllogism; as, Every man is mortal; therefore the king must die.
• noun (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.
• adjective Going before in time; prior; anterior; preceding
• adjective Presumptive.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Earlier, either in time or order.
• noun Any thing that precedes another thing, especially the cause of the second thing.
• noun An ancestor.
• noun grammar A word, phrase or clause referred to by a pronoun.
• noun logic The conditional part of a hypothetical proposition.
• noun mathematics The first term of a ratio, i.e. the term a in the ratio a:b, the other being the consequent.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun someone from whom you are descended (but usually more remote than a grandparent)
• noun the referent of an anaphor; a phrase or clause that is referred to by an anaphoric pronoun
• noun anything that precedes something similar in time
• noun a preceding occurrence or cause or event
• adjective preceding in time or order