deficient vs weakness

deficient

noun
  • A person who is deficient. 

adj
  • Insufficient or inadequate in amount. 

  • Lacking something essential; often construed with in. 

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

weakness

noun
  • The condition of being weak. 

  • An inadequate quality; fault 

  • A special fondness or desire. 

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