Irregular1. (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.
2. (n.) One who is not regular; especially, a soldier not in regular service.
Thesaurus Entries
Bohemian, Charley, Mickey Mouse, VC, Vietcong, aberrant, abnormal, actionable, adrift, affable, afloat, against the law, aimless, alternating, amorphous, anamorphous, anarchic, anarchistic, anomalistic, anomalous, anomic, askew, asymmetric, asymmetrical, atypical, base, bent, bizarre, black-market, bootleg, bowed, broken, broken off, bumpy, bushfighter, bushwhacker, capricious, careening, casual, catchy, changeable, changeful, changing, chargeable, cheap, cheesy, chopped-off, choppy, coarse, coarse-grained, cockeyed, common, contorted, contraband, contrary to law, cordial, corrugated, craggy, crank, crankish, cranky, crazy, criminal, crooked, cross-grained, crotchety, crumpled, crunched, decousu, degage, designless, desultory, deviable, deviant, deviating, deviative, deviatory, different, disarticulated, disconnected, discontinued, discontinuous, discrete, disjunct, disjunctive, disordered, disorderly, disparate, dispersed, disproportional, disproportionate, distorted, divaricate, divergent, diversified, diversiform, dizzy, dotty, easy, easygoing, eccentric, episodic, erose, erratic, exceptional, extraordinary, familiar, fast and loose, felonious, fey, fickle, fitful, flaky, flawed, flickering, flighty, flitting, fluctuating, folksy, formless, fourth-class, freakish, freaky, free and easy, frivolous, funny, giddy, gracious, grainy, granulated, gratuitous, guerrilla, guttering, halting, haphazard, haymish, herky-jerky, heteroclite, heteromorphic, hit-or-miss, homely, homespun, homey, horripilant, idiocratic, idiosyncratic, ill-matched, ill-sorted, illegal, illegitimate, illicit, immethodical, impermissible, impetuous, impulsive, inadequate, inchoate, incoherent, inconsistent, inconstant, indecisive, indiscriminate, inequal, inferior, infirm, informal, insufficient, intermittent, intermitting, interrupted, irresolute, irresponsible, jagged, jerky, jolty, justiciable, kinky, kooky, labyrinthine, lawless, linsey-woolsey, loose, lopsided, low-class, low-grade, low-quality, low-test, lumpy, lurching, maggoty, maquis, maquisard, mazy, mean, meaningless, mercurial, mismatched, misshapen, moody, motley, mutable, natural, nonconforming, nonconformist, nonconstitutional, noncontinuous, nonlegal, nonlicit, nonlinear, nonsequential, nonserial, nonstandard, nonsymmetric, nonsymmetrical, nonsystematic, nonuniform, nutty, occasional, odd, oddball, off-balance, off-key, offbeat, offhand, offhanded, one-sided, orderless, out of proportion, outlaw, outlawed, overbalanced, paltry, parenthetic, partisan, patchy, patriot, peculiar, pimply, pitted, plain, planless, pluralistic, pocky, poor, potholed, promiscuous, punishable, punk, purposeless, queer, quirky, ragged, rambling, random