consistency vs irregularity

consistency

noun
  • Freedom from contradiction; the state of a system of axioms such that none of the propositions deduced from them are mutually contradictory. 

  • Correspondence or compatibility. 

  • Reliability or uniformity; the quality of being consistent. 

  • The degree of viscosity of something. 

  • Local coherence. 

irregularity

noun
  • A violation of rules. 

  • An object or event that is not regular or ordinary. 

  • An instance of being irregular. 

  • Irregular bowel movement (e.g. diarrhea or constipation). 

  • The state or condition of being irregular, or the extent to which something is irregular. 

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