irregularity vs practice

irregularity

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

  • A violation of rules. 

  • 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. 

practice

noun
  • A customary action, habit, or behaviour; a manner or routine. 

  • The ongoing pursuit of a craft or profession, particularly in medicine or the fine arts. 

  • Actual operation or experiment, in contrast to theory. 

  • A place where a professional service is provided, such as a general practice. 

  • The observance of religious duties that a church requires of its members. 

  • An organized event for the purpose of performing such repetition. 

  • The form, manner, and order of conducting and carrying on suits and prosecutions through their various stages, according to the principles of law and the rules laid down by the courts. 

  • Skilful or artful management; dexterity in contrivance or the use of means; stratagem; artifice. 

  • Repetition of an activity to improve a skill. 

  • A easy and concise method of applying the rules of arithmetic to questions which occur in trade and business. 

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