(noun, adjective)


1. contrary to rule or accepted order or general practice

- irregular hiring practices

Similar word(s): illegal, asymmetrical, crooked, casual, occasional, improper, unconventional, unlawful, randomised, randomized, strong, unrhythmic, unrhythmical, rough, unsmooth, unsteady, asymmetric, asymmetrical, unsystematic

2. not occurring at a regular rate or fixed intervals

- an irregular heartbeat

Similar word(s): sporadic, unpredictable

3. (used of the military) not belonging to or engaged in by regular army forces

- irregular troops

- irregular warfare

Similar word(s): partisan, partizan

4. (of solids) not having clear dimensions that can be measured; volume must be determined with the principle of liquid displacement

5. failing to meet a standard of manufacture due to an imperfection

- an irregular pair of jeans

Similar word(s): imperfect

6. deviating from normal expectations; somewhat odd, strange, or abnormal

- highly irregular behavior

Similar word(s): abnormal, unnatural, atypical

7. lacking continuity or regularity

- an irregular worker

Similar word(s): temporary

8. (of a surface or shape); not level or flat or symmetrical

- walking was difficult on the irregular cobblestoned surface

Similar word(s): uneven

9. independent in behavior or thought

- she led a somewhat irregular private life

Similar word(s): unconventional, maverick, unorthodox


1. a member of an irregular armed force that fights a stronger force by sabotage and harassment

Similar word(s): guerilla, guerrilla, insurgent

Definition categories: person, warrior

2. merchandise that has imperfections; usually sold at a reduced price without the brand name

Similar word(s): second

Definition categories: man–made, merchandise, product, ware