noun

1. Any thing that precedes another thing, especially the cause of the second thing.

2. An ancestor.

3. (grammar) A word, phrase or clause referred to by a pronoun.

Synonyms: ascendant, ascendent, forebear, forefather, forerunner, predecessor, progenitor, precedent

adjective

1. Earlier, either in time or in order.

   “an antecedent cause”

2. Presumptive.

   “an antecedent improbability”