lineation vs silhouette

lineation

noun
  • The way in which line breaks are inserted in a poem 

  • A linear feature in rock, often structural 

silhouette

noun
  • An illustrated outline filled in with a solid color(s), usually only black, and intended to represent the shape of an object without revealing any other visual details; a similar appearance produced when the object being viewed is situated in relative darkness with brighter lighting behind it; a profile portrait in black, such as a shadow appears to be. 

verb
  • To represent by a silhouette; to project upon a background, so as to be like a silhouette. 

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