deficient vs substantial

deficient

adj
  • Lacking something essential; often construed with in. 

  • Insufficient or inadequate in amount. 

  • Of a number n, Having the sum of divisors σ(n)<2n, or, equivalently, the sum of proper divisors (or aliquot sum) s(n). 

noun
  • A person who is deficient. 

substantial

adj
  • Most important; essential. 

  • Not imaginary; real; actual; true; veritable. 

  • Having a substance; actually existing. 

  • Corporeal; material; firm. 

  • Possessed of goods or an estate; moderately wealthy. 

  • Satisfying; having sufficient substance to be nourishing or filling. 

  • Large in size, quantity, or value; ample; significant. 

  • Having good substance; strong; stout; solid; firm. 

noun
  • Anything having substance; an essential part. 

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