all-important vs central

all-important

adj

  • Very important; vital or crucial. 

central

adj

  • Being very important, or key to something. 

  • Having or containing the centre of something. 

  • Being in the centre. 

  • Exerting its action towards the peripheral organs. 

noun

  • centre 

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