irregular

непра́вильный

Nonstandard; not conforming to rules or expectations

• The surface of the moon is irregular.

  Поверхность луны неровная.

  Tatoeba · CM · CC BY 2.0 FR

непра́вильный

Of a surface, rough

непра́вильный

Without symmetry, regularity, or uniformity

непра́вильный

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

непра́вильный

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

непра́вильный

Of a word, not following the regular or expected patterns of inflection in a given languageредкое

непра́вильный

Having abnormal bowel movements at inconsistent intervalsредкое