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).

Adjective

(en adjective)

(often capitalized, see (Mercurial)) Pertaining to the planet Mercury.

(often capitalized, see (Mercurial)) Pertaining to the Roman god Mercury, the god of trade; hence, money-making; crafty..

* J. Q. Adams

the mercurial wand of commerce

(astrology) Born under the influence of the planet Mercury, and having such characteristics.

Of, or pertaining to the element mercury; containing mercury; caused by the action of mercury or quicksilver.

Having a volatile or lively character; quick-witted, changeable, animated.

* 1723 , Charles Walker, Memoirs of Sally Salisbury , I:

From the natural Mercurial Briskness of her Temper, a sedentary Life had ever been her Aversion [...].