grey matter vs orientation

grey matter

noun
  • Brains; a person's ability to think. 

  • A collection of cell bodies and (usually) dendritic connections, in contrast to white matter. 

  • Literal brains as a general substance. 

orientation

noun
  • The ability to orient, or the process of so doing. 

  • The construction of a Christian church to have its aisle in an east-west direction with the altar at the east end. 

  • The determination of the relative position of something or someone. 

  • Events to orient new students at a school; events to help new students become familiar with a school. 

  • The choice of which ordered bases are "positively" oriented and which are "negatively" oriented on a real vector space. 

  • The relative physical position or direction of something. 

  • An adjustment to a new environment. 

  • The direction of print across the page; landscape or portrait. 

  • The designation of a parametrised curve as "positively" or "negatively" oriented (or "nonorientable"); the analogous description of a surface or hypersurface. 

  • An introduction to a (new) environment. 

  • An inclination, tendency or direction. 

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