irregular

adj. 1 not regular; unsymmetrical, uneven; varying in form. 2 not occurring at regular intervals. 3 contrary to a rule, principle, or custom; abnormal. 4 (of troops) not belonging to the regular army. 5 (of a verb, noun, etc.) Not inflected according to the usual rules. 6 disorderly. n. (in pl.) Irregular troops.  irregularity n. (pl. -ies). Irregularly adv.

a. Not regular; not conforming to a law, method, or usage recognized as the general rule; not according to common form; not conformable to nature, to the rules of moral rectitude, or to established principles; not normal; unnatural; immethodical; unsymmetrical; erratic; no straight; not uniform; as, an irregular line; an irregular figure; an irregular verse; an irregular physician; an irregular proceeding; irregular motion; irregular conduct, etc. Cf. Regular.