Adjective

(-)

Arising as the result of an event, inherent

(physics) (of a stream of particles or radiation ) falling on or striking a surface (e.g. "The incident light illuminated the surface.")

Coming or happening accidentally; not in the usual course of things; not in connection with the main design; not according to expectation; casual; fortuitous.

* Hooker

As the ordinary course of common affairs is disposed of by general laws, so likewise men's rarer incident necessities and utilities should be with special equity considered.

Liable to happen; apt to occur; befalling; hence, naturally happening or appertaining.

* Milton

all chances incident to man's frail life

* Milward

the studies incident to his profession

(legal) Dependent upon, or appertaining to, another thing, called the principal.

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).