Adjective

(en adjective)

Not formal or ceremonious.

*, chapter=3

, title= The Mirror and the Lamp , passage=One saint's day in mid-term a certain newly appointed suffragan-bishop came to the school chapel, and there preached on “The Inner Life.”  He at once secured attention by his informal method, and when presently the coughing of Jarvis […] interrupted the sermon, he altogether captivated his audience with a remark about cough lozenges being cheap and easily procurable.}}

Not in accord with the usual regulations.

Suited for everyday use.

(of language) Reflecting everyday, non-ceremonious usage.

(gardening) Not organized; not structured or planned.

Adjective

(en adjective)

Nonstandard; not conforming to rules or expectations.

* {{quote-book

, year = 1967 , first = Barbara , last = Sleigh , authorlink = Barbara Sleigh , title = (Jessamy) , edition = 1993 , location = Sevenoaks, Kent , publisher=Bloomsbury , isbn = 0 340 19547 9 , page = 33 , url = , passage = ‘ “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. [...] ’ }}

Of a surface, rough.

Without symmetry, regularity, or uniformity.

*{{quote-book, year=1944, author=(w)

, title= The Three Corpse Trick, chapter=5 , passage=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 original common.}}

* {{quote-magazine, date=2013-01-01, author=Paul Bartel, Ashli Moore

, volume=101, issue=1, page=47–48, magazine=(American Scientist) , title= Avian Migration: The Ultimate Red-Eye Flight , passage=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 siskins (Spinus pinus ) undergo an irregular , nomadic type of nocturnal migration.}}

* {{quote-magazine, date=2013-07-19, author= Ian Sample

, volume=189, issue=6, page=34, magazine=(The Guardian Weekly) , title= Irregular bedtimes may affect children's brains , passage=Irregular bedtimes may disrupt healthy brain development in young children, according to a study of intelligence and sleeping habits.  ¶ Going to bed at a different time each night affected girls more than boys, but both fared worse on mental tasks than children who had a set bedtime, researchers found.}}

Not regular; having sides that are not equal or angles that are not equal.

Whose faces are not all regular polygons (or are not equally inclined to each other).