apical vs central

apical

adj
  • Of or connected with the apex. 

  • Produced with the tip of the tongue. 

  • Situated at the growing tip of the plant or its roots, in comparison with intercalary growth situated between zones of permanent tissue. 

noun
  • A sound produced by obstructing the air passage with the tip of the tongue. 

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 apical and central occurred in a corpus of books? (source: Google Ngram Viewer )