beginning vs precursor

beginning

noun
  • That which begins or originates something; the source or first cause. 

  • The act of doing that which begins anything; commencement of an action, state, or space of time; entrance into being or upon a course; the first act, effort, or state of a succession of acts or states. 

  • The initial portion of some extended thing. 

  • That which is begun; a rudiment or element. 

adj
  • Of or relating to the first portion of some extended thing. 

precursor

noun
  • That which precurses: a forerunner, predecessor, or indicator of approaching events. 

  • One of the compounds that participates in the chemical reaction that produces another compound. 

adj
  • Caused by the following symbol. 

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