crawfish vs regrade

crawfish

verb
  • To backpedal, desert or withdraw (also used with out). 

noun
  • Various marine crustaceans, rock lobster; especially Jasus lalandii, the Cape crawfish. 

  • Various freshwater crustaceans, crayfish. 

  • A slur against Anglo-Canadians used in some corners of Quebec (including the Gaspé). 

regrade

verb
  • To regroup or reassign. 

  • To change the classification of (potentially secret documentation). 

  • To grade again, give a new grade or grading to. 

noun
  • The act or process of grading again. 

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