central vs inward

central

adj
  • Having or containing the centre of something. 

  • Being in the centre. 

  • Exerting its action towards the peripheral organs. 

  • Being very important, or key to something. 

noun
  • centre 

inward

adj
  • Situated on the inside; that is within, inner; belonging to the inside. 

  • Not superficially obvious, inner, not expressed, especially relating to mental or spiritual faculties as opposed to external ones. 

  • Moving or tending toward the inside. 

adv
  • Towards the inside. 

  • Towards one’s mind, thoughts, or internal self. 

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