havering vs perturbation

havering

noun
  • Indecision, indecisive behaviour. 

adj
  • Hesitant; indecisive. 

  • Long-winded 

perturbation

noun
  • Agitation; the state of being perturbed 

  • Variation in an orbit due to the influence of external bodies 

  • A small change in a physical system, or more broadly any definable system (such as a biological or economic system) 

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