disturbance vs encroachment

disturbance

noun
  • The act of disturbing, being disturbed. 

  • A noisy commotion that causes a hubbub or interruption. 

  • Something that disturbs. 

  • An interruption of that which is normal or regular. 

  • A serious mental imbalance or illness. 

encroachment

noun
  • An intrusion upon another's possessions or rights; infringement. 

  • That which is gained by such unlawful intrusion. 

  • An unlawful diminution of the possessions of another. 

  • An entry into a place or area that was previously uncommon; an advance beyond former borders; intrusion; incursion. 

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