Ante diluvian is a term used to describe something that is very old or ancient. The antonyms of ante diluvian are "modern" and "contemporary". Modern refers to something that is current and up-to-date while contemporary refers to something that is in the present time. Other antonyms for ante diluvian include "recent", "new" and "fresh". These words represent the opposite of something that is old and outdated. Using antonyms can help provide a contrast and a better understanding of the meaning of a word. Ante diluvian is still a useful term in certain contexts, such as in archaeology and paleontology, where it is used to describe objects or creatures that existed before the time of the great flood.