Irregular
- Accounting irregularity
- Anomaly (disambiguation)
- Arrhythmia
- Baker Street Irregulars
- Canonical impediment
- Constipation
- Irregular bone
- Irregular chess opening
- Irregular galaxy
- Irregular inflection
- Irregular military
- Irregular moon
- Irregular variable
- Irregular verb
- Irregularity index
- Irregularity of a surface
- Irregularity of distributions
- Regular (disambiguation)
- The Irregulars