central vs middle

central

noun

  • centre 

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. 

middle

noun

  • A centre, midpoint. 

  • The part between the beginning and the end. 

  • The middle stump. 

  • The central part of a human body; the waist. 

  • The middle voice. 

adj

  • Pertaining to the middle voice. 

  • Located in the middle; in between. 

  • Central. 

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