do for vs ixnay

do for

verb
  • To doom; to bring about the demise of someone. 

  • Used other than figuratively or idiomatically: see do, for. 

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 do for and ixnay occurred in a corpus of books? (source: Google Ngram Viewer )