What is the meaning of Irregular?

Nonstandard; not conforming to rules or expectations.

Of a surface, rough.

Without symmetry, regularity, or uniformity.

Of a polygon, not regular; having sides that are not equal or angles that are not equal.

Of a polyhedron, whose faces are not all regular polygons (or are not equally inclined to each other).

Of a word, 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