Definition of irregulars:
(adj) :
Nonstandard; not conforming to rules or expectations.
(adj) :
Without symmetry, regularity, or uniformity.
(adj) :
(grammar, of a word) Not following the regular or expected patterns of inflection in a given language.
(adj) :
Rough (of a surface).
(adj) :
(geometry, of a polygon) Not regular; having sides that are not equal or angles that are not equal.
(adj) :
(geometry, of a polyhedron) Whose faces are not all regular polygons (or are not equally inclined to each other).