undertaking vs wavering

undertaking

noun
  • A promise or pledge; a guarantee. 

  • That which is undertaken; any business, work, or project which a person engages in, or attempts to perform; an enterprise. 

  • The business of an undertaker, or the management of funerals. 

  • The act of one who undertakes (in either sense). 

wavering

adj
  • Being in doubt; indecisive. 

  • Fluctuating, uncertain, undetermined, unsteady. 

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