antedating

verb

  1. To occur before an event or time; to exist further back in time.

  2. To assign a date to a document or action earlier than the actual date; to backdate.

  3. To find earlier citational evidence for a term.

Synonyms: backdate, foredate, predate
Antonyms: overdate, postdate, postdate

noun

  1. The action of marking with an earlier date.

  2. An earlier citation of a lexical item.

    "The new edition of the dictionary contains several antedatings."