flood vs rain

flood

verb
  • To provide (someone or something) with a larger number or quantity of something than can easily be dealt with. 

  • To bleed profusely, as after childbirth. 

  • To cover or partly fill as if by a flood. 

  • To overflow, as by water from excessive rainfall. 

  • To paste numerous lines of text to (a chat system) in order to disrupt the conversation. 

noun
  • An overflow (usually disastrous) of water from a lake or other body of water due to excessive rainfall or other input of water. 

  • A large number or quantity of anything appearing more rapidly than can easily be dealt with. 

  • The flowing in of the tide, opposed to the ebb. 

  • A floodlight. 

  • Menstrual discharge; menses. 

rain

verb
  • To issue (something) in large quantities. 

  • To have rain fall from the sky. 

  • To fall as or like rain. 

noun
  • Any matter moving or falling, usually through air, and especially if liquid or otherwise figuratively identifiable with raindrops. 

  • Condensed water falling from a cloud. 

  • An instance of particles or larger pieces of matter moving or falling through air. 

How often have the words flood and rain occurred in a corpus of books? (source: Google Ngram Viewer )