encroachment vs intrusion

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. 

intrusion

noun
  • The forcible inclusion or entry of an external group or individual; the act of intruding. 

  • The insertion of a phoneme into the pronunciation of a word despite its absence from the spelling. (e.g. intrusive r) 

  • A structure that lies within a historic district but is nonhistoric and irrelevant to the district. 

  • Magma forced into other rock formations; the rock formed when such magma solidifies. 

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