In grammar, an antecedent is the noun to which a relative or other pronoun refers; as, Solomon was the prince who built the temple, where the word prince is the antecedent of who.
In logic, an antecedent is that member of a hypothetical or conditional proposition which contains the condition, and which is introduced by if or some equivalent word or words; as, if the sun is fixed, the earth must move. Here the first and conditional proposition is the antecedent, the second the consequent. Research Antecedent