vacillate vs zig

vacillate

verb
  • To swing indecisively from one course of action or opinion to another. 

  • To sway unsteadily from one side to the other; oscillate. 

zig

verb
  • To make such a turn. 

noun
  • A sudden or sharp turn or change of direction. 

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