1650s, "fact or act of coming before (another or others) in time, place, or order," from Latin antecedens "a going before" (see antecedent). From 1660s in specific sense in astronomy, "apparent contrary motion of a planet" (from east to west). Related: Antecedency (1590s).
ante
ante meridiem
ant-eater
ante-bellum
antecede
antecedence
antecedent
antecessor
antechamber
antedate
antediluvian