\Di*lu"vi*al\, 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.

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.