impression vs separation

impression

noun
  • The indentation or depression made by the pressure of one object on or into another. 

  • set of copies of a publication printed at one time having the same content, layout, pagination, etc. 

  • The vivid perception of something as it is experienced, in contrast to ideas or thoughts drawn from memory or the imagination. 

  • An online advertising performance metric representing an instance where an ad is shown once. 

  • A vague recalling of an event, a belief. 

  • An outward appearance. 

  • A print on paper from a wood block, metal plate, etc. 

  • An impersonation, an imitation of the mannerisms of another individual. 

  • The first coat of colour, such as the priming in house-painting etc. 

  • The overall effect of something, e.g., on a person. 

verb
  • To manipulate a blank key within a lock so as to mark it with impressions of the shape of the lock, which facilitates creation of a duplicate key. 

separation

noun
  • The act of disuniting two or more things, or the condition of being separated. 

  • Departure from active duty, while not necessarily leaving the service entirely. 

  • An agreement legalizing such an arrangement. 

  • An object that separates two spaces. 

  • The act or condition of two or more people being separated from one another. 

  • The place at which a division occurs. 

  • An interval, gap or space that separates things or people. 

  • The act or condition of a married couple living in separate homes while remaining legally married. 

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