The process of making something irregular. / (linguistics) An irregular form.

(transitive) To make irregular.

A verb that does not follow the normal rules for its conjugation.

plural of irregular verb

(astronomy) A galaxy which is has no spirals and is not elliptical.

(idiomatic) Irregularly, occurring in irregular time intervals or patterns.

plural of irregular galaxy

(mathematics) Any odd prime number that is not a regular prime.

plural of irregular prime

Warfare in which one or more combatants are irregulars (such as partisans, guerrillas or insurgents) rather than regular military forces.