alteration vs departure

alteration

noun
  • The act of altering or making different. 

  • The state of being altered; a change made in the form or nature of a thing; a changed condition. 

departure

noun
  • The act of departing or something that has departed. 

  • A deviation from a plan or procedure. 

  • There are several significant departures, however, from current practice. 

  • The distance due east or west made by a ship in its course reckoned in plane sailing as the product of the distance sailed and the sine of the angle made by the course with the meridian. 

  • The difference in easting between the two ends of a line or curve. 

  • The desertion by a party to any pleading of the ground taken by him in his last antecedent pleading, and the adoption of another 

  • A death. 

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