- without symmetry, even shape, formal arrangement, etc.: an irregular pattern.
- not characterized by any fixed principle, method, continuity, or rate: irregular intervals.
- not conforming to established rules, customs, etiquette, morality, etc.: highly irregular behavior.
- not according to rule, or to the accepted principle, method, course, order, etc.
- not conforming to the prevalent pattern or patterns of formation, inflection, construction, etc., of a language; having a rule descriptive of a very small number of items: The English verbs “keep” and “see” are irregular in their inflections.
- (formerly, of troops) not belonging to an organized group of the established forces.
- flawed, damaged, or failing to meet a specific standard of manufacture: a sale of irregular shirts.
- Botany.
- not uniform.
- (of a flower) having the members of some or all of its floral circles or whorls differing from one another in size or shape, or extent of union.
- deviating or experiencing deviations from a normally regular or cyclic body function, as bowel habits or menstruation.
- (of a stock or commodity market) of mixed market activity; showing no clear up or down trend.
- a person or thing that is irregular.
- a product or material that does not meet specifications or standards of the manufacturer, as one having imperfections in its pattern.
- a soldier or combatant not of a regular military force, as a guerrilla or partisan.
- lacking uniformity or symmetry; uneven in shape, position, arrangement, etc
- not occurring at expected or equal intervals
- differing from the normal or accepted practice or routine
- not according to established standards of behaviour; unconventional
- (of the formation, inflections, or derivations of a word) not following the usual pattern of formation in a language, as English plurals ending other than in -s or -es
- of or relating to guerrillas or volunteers not belonging to regular forces
- (of flowers) having any of their parts, esp petals, differing in size, shape, etc; asymmetric
- (of merchandise) not up to the manufacturer's standards or specifications; flawed; imperfect
- a soldier not in a regular army
- imperfect or flawed merchandise
