D defs.my
Entry 2 senses Webster, 1913

Cataclysm

/kăt'-ək-lĭsˌ-əm/ · Cat·a·clysm · IPA /ˈkætəˌklɪzm̩/
01 n. An extensive overflow or sweeping flood of water; a deluge.
  1. 1.
    An extensive overflow or sweeping flood of water; a deluge.
  2. 2.
    Any violent catastrophe, involving sudden and extensive changes of the earth's surface.(Geol.)