equilibrium vs irregularity

equilibrium

noun
  • Mental balance. 

  • The condition of a system in which competing influences are balanced, resulting in no net change. 

  • The state of a body at rest or in uniform motion in which the resultant of all forces on it is zero. 

  • The state of a reaction in which the rates of the forward and reverse reactions are the same. 

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 equilibrium and irregularity occurred in a corpus of books? (source: Google Ngram Viewer )