come about vs variate

come about

verb
  • To change; to come round. 

  • To come to pass; to develop; to occur; to take place; to happen; to exist. 

  • To tack; to change tack; to maneuver the bow of a sailing vessel across the wind so that the wind changes from one side of the vessel to the other; to position a boat with respect to the wind after tacking. See also come to. 

variate

verb
  • To alter; to vary; to make or become different. 

noun
  • The measured magnitude of a variable. 

  • random variable 

  • A variable, often the set of x values plotted on a graph. 

  • A measurable quantity capable of taking on a number of values. 

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