irregular

Nonstandard; not conforming to rules or expectations.

Adjective

  1. Nonstandard; not conforming to rules or expectations.
    • ‘ “It would be most irregular Grandpa!” says Miss Cecily frowning and tapping her foot. “Well, we’re a pretty irregular family so that’s neither here nor there,” says the old man, impish like. [...] ’ - 1967, Barbara...
  2. Of a surface, rough.
  3. Without symmetry, regularity, or uniformity.
    • The hovel stood in the centre of what had once been a vegetable garden, but was now a patch of rank weeds. Surrounding this, almost like a zareba, was an irregular ring of gorse and brambles, an unclaimed vestige of the...
    • Near by, where the crystal clear River Llugwy is crossed by a bridge, stands a small and ancient church built of massive, irregular boulders. - 1980, AA Book of British Villages, Drive Publications Ltd, page 100:
    • Many of these classic methods are still used, with some modern improvements. For example, with the aid of special microphones and automated sound detection software, ornithologists recently reported […] that pine...
  4. Of a polygon, not regular; having sides that are not equal or angles that are not equal.
  5. Of a polyhedron, whose faces are not all regular polygons (or are not equally inclined to each other).
  6. Of a word, not following the regular or expected patterns of inflection in a given language.
    • "Calves", "cacti", and "children" are irregular plurals.
    • "To buy" is an irregular English verb: its past simple and past participle tense is "bought".
    • I hate learning all the irregular conjugations in French.

Origin

From Middle English irreguler, from Old French irreguler, from Medieval Latin or Late Latin irrēgulāris, from in- + regularis, equivalent to ir- + regular.

Forms

more irregular most irregular

Synonyms

abnormal singular coarse salebrous unstable unsteady heteroclite

Antonyms

regular

Derived

irregular galaxy irregularist irregularity irregularization irregularize irregularly irregularness irregular prime irregular prism irregular verb irregular warfare nonirregular on an irregular basis regioirregular stereoirregular

Noun

  1. A soldier who is not a member of an official military force and who may not use regular army tactics.
  2. One who does not regularly attend a venue.
    • There's one neighborhood tavern where the regulars and irregulars go after a hard day to unlax and rewind, throw back a few, and just hang out - you know the one. - 2015, Brian Cook, Hands Across The Sea, page 190:

Forms

irregulars

Derived

Baker Street Irregular