adjacent vs central

adjacent

adj
  • Lying next to, close, or contiguous; neighboring; bordering on. 

  • Related to; suggestive of; bordering on. 

  • Just before, after, or facing. 

prep
  • Next to; beside. 

  • Related to; suggestive of; bordering on. 

noun
  • Something that lies next to something else, especially the side of a right triangle that is neither the hypotenuse nor the opposite. 

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 

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