Postdate \Post"date`\, v. t. [imp. & p. p. {Postdated}; p. pr. & vb. n. {Postdating}.] [Pref. post- + date.] 1. To date after the real time; as, to postdate a contract, that is, to date it later than the time when it was in fact made. 2. To affix a date to after the event.