equivocate vs stall for time

equivocate

verb
  • To render equivocal or ambiguous. 

  • To speak using double meaning; to speak ambiguously, unclearly or doubtfully, with intent to deceive. 

stall for time

verb
  • To intentionally cause a delay; to stop; to wait. 

How often have the words equivocate and stall for time occurred in a corpus of books? (source: Google Ngram Viewer )