<p><strong>Adjective</strong></p><ul><li>preceding; prior: an antecedent event.</li><li>Synonyms: preexistent, precursory</li><li>Antonyms: subsequent</li></ul><p><strong>Noun</strong></p><ul><li>a preceding circumstance, event, object, style, phenomenon, etc.</li><li>Synonyms: ancestor, forerunner, precursor</li><li>Antonyms: successor</li><li>antecedents, ancestors.</li><li>the history, events, characteristics, etc., of one's earlier life: Little is known about his birth and antecedents.</li><li>Grammar: a word, phrase, or clause, usually a substantive, that is replaced by a pronoun or other substitute later, or occasionally earlier, in the same or in another, usually subsequent, sentence.</li><li>Mathematics: the first term of a ratio; the first or third term of a proportion.</li><li>Logic: the conditional element in a proposition, as “Caesar conquered Gaul,” in “If Caesar conquered Gaul, he was a great general.”</li></ul>