Synonyms of irregular

irregular 1 of 2

adjective

i-ˈre-gyə-lər 

1

as in abnormal

departing from some accepted standard of what is normal

it was a bank customer's slightly irregular behavior that made people suspicious

Synonyms & Similar Words

• abnormal
• unnatural
• unusual
• anomalous
• atypical
• uncommon
• aberrant
• deviant
• untypical
• odd
• extraordinary
• deviate
• aberrational
• devious
• eccentric
• bizarre
• weird
• strange
• unconventional
• unrepresentative
• peculiar
• funny
• rare
• curious
• remarkable
• idiosyncratic
• unwonted
• screwy
• quirky
• wacky
• unorthodox
• kinky
• quaint
• freakish
• out-of-the-way
• outlandish
• preternatural
• queer
• whacky
• uncustomary
• nonconformist
• wild
• outré
• way-out
• queerish
• far-out

Antonyms & Near Antonyms

• normal
• regular
• typical
• natural
• standard
• ordinary
• common
• familiar
• routine
• everyday
• commonplace
• unremarkable
• usual
• customary
• characteristic
• unexceptional
• average
• workaday
• run-of-the-mill
• run-of-the-mine
• representative
• run-of-mine
• archetypal
• wonted
• archetypical

2

as in sporadic

lacking in steadiness or regularity of occurrence

irregular mail delivery to the island

Synonyms & Similar Words

• sporadic
• occasional
• intermittent
• sudden
• erratic
• discontinuous
• unpredictable
• unsteady
• violent
• casual
• spasmodic
• spastic
• aperiodic
• fitful
• episodic
• episodical
• spotty
• volatile
• choppy
• random
• catchy
• haphazard
• scattered
• fragmentary
• changing
• changeful
• varying
• interrupted
• broken
• arbitrary
• unstable
• uncertain
• convulsive
• odd
• aimless
• disconnected
• stray
• capricious
• unsettled
• fluctuating
• variable
• inconstant
• desultory
• mutable
• mercurial
• slapdash
• changeable
• fluid
• temperamental
• hit-or-miss
• hit-and-miss
• fickle
• wavering
• flickery

Antonyms & Near Antonyms

• continuous
• regular
• periodic
• constant
• habitual
• steady
• uniform
• stable
• repeated
• stationary
• even
• systematic
• unchanging
• orderly
• equable
• changeless
• methodical
• unvarying
• unrelenting
• unremitting
• unwavering
• methodic

3

as in uneven

not having a level or smooth surface

although the moon looks smooth from here, it actually has a very bumpy and irregular surface

Synonyms & Similar Words

• uneven
• jagged
• rough
• rugged
• broken
• ragged
• wavy
• lumpy
• coarse
• bumpy
• roughened
• pebbly
• scraggy
• unbalanced
• lopsided
• undulating
• inexact
• undulatory
• rutted
• harsh
• unaligned
• nonuniform
• pitted
• knobby
• pocked
• knobbly
• scratchy
• nubby
• rutty
• scraggly
• knurled
• nubbly
• sandpapery
• burred
• knurly

Antonyms & Near Antonyms

• smooth
• flat
• regular
• uniform
• level
• even
• exact
• true
• aligned
• horizontal
• vertical
• plane
• straight
• tabular
• alined
• flush
• plumb

4

as in informal

not rigidly following established form, custom, or rules

the request is irregular, but I'll allow it

Synonyms & Similar Words

• informal
• unconventional
• unorthodox
• unceremonious
• unofficial
• heterodox
• unauthorized
• casual
• relaxed
• lax
• familiar
• free and easy
• easygoing
• loose
• offhand
• ultracasual

Antonyms & Near Antonyms

• regular
• conventional
• formal
• routine
• ceremonial
• orthodox
• proper
• correct
• rigid
• ceremonious
• stiff
• restrained
• decorous
• constrained
• inhibited
• stuffy
• uptight

5

as in changing

not staying constant

irregular gusts of wind

Synonyms & Similar Words

• changing
• uneven
• varying
• unequal
• unstable
• changeful
• volatile
• erratic
• inconsistent
• fluctuating
• unsteady
• variable
• uncertain
• capricious
• changeable
• mercurial
• unsettled
• inconstant
• fluid
• fickle
• mutable
• choppy

Antonyms & Near Antonyms

• constant
• stable
• steady
• regular
• unchanging
• unvarying
• changeless

irregular

2 of 2

noun

as in guerilla

Related Words

• guerilla
• partizan
• guerrilla
• paramilitary
• soldier
• regular
• counterguerrilla
• warrior
• counterguerilla
• legionary
• serviceman
• partisan
• trooper
• legionnaire
• cavalier
• fighter
• dragoon
• cavalryman
• cuirassier
• marine
• servicewoman
• dogface
• man-at-arms
• foot soldier
• infantryman
• carabinier
• doughboy
• raider
• grunt
• commando
• footman
• ranger
• carabineer
• artilleryman
• musketeer
• rifleman
• archer
• cannoneer
• jarhead
• gunner
• mortarman
• crossbowman

Dissimilar Words

• civilian
• noncombatant

Synonym Chooser

How is the word irregular distinct from other similar adjectives?

The words anomalous and unnatural are common synonyms of irregular. While all three words mean "not conforming to rule, law, or custom," irregular implies not conforming to a law or regulation imposed for the sake of uniformity in method, practice, or conduct.

concerned about his irregular behavior

When would anomalous be a good substitute for irregular?

Although the words anomalous and irregular have much in common, anomalous implies not conforming to what might be expected because of the class or type to which it belongs or the laws that govern its existence.

her drive made her an anomalous figure in a sleepy organization

When could unnatural be used to replace irregular?

The meanings of unnatural and irregular largely overlap; however, unnatural suggests what is contrary to nature or to principles or standards felt to be essential to the well-being of civilized society.

prisoners treated with unnatural cruelty

Example Sentences

Recent Examples of irregular

Adjective

Turkish troops then began shelling Kurdish towns in Syria, and Turkish forces pushed forward, irregulars executing people in ditches along the road. —Time, 14 Nov. 2019

Pakistani irregulars invaded, India intervened, and the two countries fought to a stalemate. —Washington Post, 15 Feb. 2019

Noun

When gone untreated, Lyme disease can produce a wide range of symptoms depending on the stage of infection, including fever, rash, facial paralysis, irregular heartbeat and arthritis. —Rebecca Morin, USA Today, 1 Aug. 2025

Then, there are irregular galaxies, which cannot be neatly categorized. —Katie Liu, Discover Magazine, 31 July 2025