1. (a.) Pertaining to a flood or deluge\, especially to the great deluge in the days of Noah; diluvian.

2. (a.) Effected or produced by a flood or deluge of water; -- said of coarse and imperfectly stratified deposits along ancient or existing water courses. Similar unstratified deposits were formed by the agency of ice. The time of deposition has been called the Diluvian epoch.