1. [v]  establish something as being earlier relative to something else
2. [v]  be earlier in time; go back further

ANTEDATE is a 8 letter word that starts with A.

1. \An"te*date`\, n.
   1. Prior date; a date antecedent to another which is the
      actual date.
   2. Anticipation. [Obs.] --Donne.
   

2. \An"te*date`\, v. t. [imp. & p. p. {Antedated}; p. pr.
   & vb. n. {Antedating}.]
   1. To date before the true time; to assign to an earlier
      date; thus, to antedate a deed or a bond is to give it a
      date anterior to the true time of its execution.
   2. To precede in time.
   3. To anticipate; to make before the true time.
            And antedate the bliss above.         --Pope.
            Who rather rose the day to antedate.  --Wordsworth.