neither vs not even

neither

adv
  • Similarly not. 

pron
  • Not either one of two. 

det
  • Not one of two; not either. 

  • Not either (used with nor). 

not even

adv
  • Introduces or constitutes a more emphatic negation or exclusion than "not". 

intj
  • Used to express strong disappointment or disapproval. 

How often have the words neither and not even occurred in a corpus of books? (source: Google Ngram Viewer )