central vs constructional

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 

constructional

adj
  • Of, pertaining to, or obtained by construction. 

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