Irregular

[ih-reg-yuh-ler] /ɪˈrɛg yə lər/

adjective
1.
without symmetry, even shape, formal arrangement, etc.:
an irregular pattern.
2.
not characterized by any fixed principle, method, continuity, or rate:
irregular intervals.
3.
not conforming to established rules, customs, etiquette, morality, etc.:
highly irregular behavior.
4.
not according to rule, or to the accepted principle, method, course, order, etc.
5.
Grammar. 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.
6.
Military. (formerly, of troops) not belonging to an organized group of the established forces.
7.
flawed, damaged, or failing to meet a specific standard of manufacture:
a sale of irregular shirts.
8.
Botany.

9.
deviating or experiencing deviations from a normally regular or cyclic body function, as bowel habits or menstruation.
10.
(of a stock or commodity market) of mixed market activity; showing no clear up or down trend.
noun
11.
a person or thing that is irregular.
12.
Commerce. a product or material that does not meet specifications or standards of the manufacturer, as one having imperfections in its pattern.
13.
Military. a soldier or combatant not of a regular military force, as a guerrilla or partisan.
/ɪˈrɛɡjʊlə/
adjective
1.
lacking uniformity or symmetry; uneven in shape, position, arrangement, etc
2.
not occurring at expected or equal intervals: an irregular pulse
3.
differing from the normal or accepted practice or routine
4.
not according to established standards of behaviour; unconventional
5.
(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
6.
of or relating to guerrillas or volunteers not belonging to regular forces: irregular troops
7.
(of flowers) having any of their parts, esp petals, differing in size, shape, etc; asymmetric
8.
(US) (of merchandise) not up to the manufacturer’s standards or specifications; flawed; imperfect
noun
9.
a soldier not in a regular army
10.
(often pl) (US) imperfect or flawed merchandise Compare second1 (sense 15)
adj.

late 14c., “not in conformity with Church rules,” from Old French irreguler (13c., Modern French irrégulier), from Medieval Latin irregularis, from assimilated form of in- “not, opposite of” (see in- (1)) + Latin regularis (see regular (adj.)). General sense is from late 15c.
n.

“a soldier not of the regular army,” 1747, from irregular (adj.).

irregular ir·reg·u·lar (ĭ-rěg’yə-lər)
adj.