irregularity

Short definition from Wiktionary

Noun

1. 1
   An instance of being irregular.
2. 2
   The state or condition of being irregular, or the extent to which something is irregular.
3. 3
   An object or event that is not regular or ordinary.
4. 4
   A violation of rules.
5. 5
   Irregular bowel movement (e.g. diarrhea or constipation).