What is the meaning of Irregular?

nonstandard; not conforming to rules or expectations

rough

without symmetry, regularity, or uniformity

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)

not following the regular or expected patterns of inflection in a given language

A soldier who is not a member of an official military force and who may not use regular army tactics.

One who does not regularly attend a venue.

irregular

irregular

irregular; nonstandard

irregular (not following an inflectional paradigm)

irregular, uneven, erratic, haphazard

patchy, spotty, jagged, ragged

fitful

(of a verb etc.) irregular

Source: wiktionary.org