The word "outdate" means to become obsolete, old-fashioned or out of date. There are various synonyms for "outdate" such as "archaic", "antiquated", "dated", "outmoded", and "primitive". All these words refer to something that is no longer current or relevant in today's world. "Archaic" indicates something that is outdated because it belongs to an earlier time period. "Antiquated" is used to describe something that is old-fashioned and no longer useful. "Dated" means something that is no longer up-to-date. "Outmoded" and "primitive" suggest something that has been replaced with more modern and advanced alternatives. Overall, these synonyms can help us to communicate more precisely and effectively by conveying the exact meaning we want.