portion vs prorate

portion

verb
  • To divide into amounts, as for allocation to specific purposes. 

  • To endow with a portion or inheritance. 

noun
  • An allocated amount. 

  • That which is divided off or separated, as a part from a whole; a separated part of anything. 

  • One's fate; lot. 

  • A wife's fortune; a dowry. 

  • The part of an estate given or falling to a child or heir; an inheritance. 

prorate

verb
  • To divide proportionately, especially by day; to divide pro rata. 

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