irregularity vs repetition

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. 

repetition

noun
  • The act or an instance of repeating or being repeated. 

  • The act of performing a single, controlled exercise motion. A group of repetitions is a set. 

verb
  • To petition again. 

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