disallow vs ixnay

disallow

verb
  • To reject as invalid, untrue, or improper 

  • to overrule a colonial legislation by the sovereign-in-privy council 

  • To refuse to allow 

ixnay

verb
  • To reject something. 

intj
  • No. 

noun
  • Nothing; nix; often in the phrase "ixnay on ...", indicating something that must not be mentioned, often in Pig Latin 

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