insufficient vs negligible

insufficient

adj
  • Not sufficient; lacking competent power or ability; unqualified, unequal, unfit. 

  • Not sufficient; of a type or kind that does not suffice, that does not satisfy requirements or needs. 

det
  • An inadequate quantity of; not enough. 

  • A quantity (of something) that is less than is needed. 

negligible

adj
  • Able to be neglected, ignored or excluded from consideration; too small or unimportant to be of concern. 

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