concur vs pester

concur

verb
  • To agree (in action or opinion); to have a common opinion; to coincide; to correspond. 

  • To converge. 

  • To meet in the same point; to combine or conjoin; to contribute or help towards a common object or effect. 

pester

verb
  • To bother, harass, or annoy persistently. 

noun
  • A bother or nuisance. 

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