a. [ L. diluvialis. fr. diluvium. ] 1. Of or pertaining to a flood or deluge, esp. to the great deluge in the days of Noah; diluvian. [ 1913 Webster ]

2. (Geol.) 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. [ 1913 Webster ]

n. One who explains geological phenomena by the Noachian deluge. Lyell. [ 1913 Webster ]