Word Study
nefarious
CIDE DICTIONARY
nefarious, a. [L. nefarius, fr. nefas crime, wrong; ne not + fas divine law; akin to fari to speak. See No, adv. , and Fate.].
Wicked in the extreme; abominable; iniquitous; atrociously villainous; execrable; detestably vile. [1913 Webster]
Syn. -- Iniquitous; detestable; horrible; heinious; atrocious; infamous; impious. See Iniquitous.
OXFORD DICTIONARY
nefarious, adj. wicked; iniquitous.
Derivative
nefariously adv. nefariousness n.
Etymology
L nefarius f. nefas wrong f. ne- not + fas divine law
THESAURUS
nefarious
abject, abominable, arrant, atrocious, awful, bad, base, beastly, beggarly, beneath contempt, black, blamable, blameworthy, brutal, cheesy, contemptible, corrupt, criminal, crummy, damnable, dark, debased, degenerate, degraded, deplorable, depraved, despicable, detestable, dire, dirty, disgraceful, disgusting, dreadful, egregious, enormous, evil, execrable, fetid, filthy, flagitious, flagrant, foul, fulsome, glaring, grave, grievous, gross, hateful, heinous, horrible, horrid, improper, infamous, iniquitous, knavish, lamentable, little, loathsome, lousy, low, low-down, lumpen, mangy, mean, measly, miscreant, miserable, monstrous, nasty, naughty, noisome, notorious, obnoxious, odious, offensive, outrageous, paltry, peccant, perverse, petty, pitiable, pitiful, poky, poor, putrid, rank, regrettable, reprehensible, reprobate, reptilian, repulsive, rotten, sad, scabby, scandalous, schlock, scrubby, scruffy, scummy, scurvy, shabby, shameful, shocking, shoddy, sinful, small, sordid, squalid, terrible, too bad, unclean, unforgivable, unmentionable, unpardonable, unspeakable, unworthy, vicious, vile, villainous, wicked, woeful, worst, worthless, wretched, wrongROGET THESAURUS
nefarious
Vice
N vice, evil-doing, evil courses, wrongdoing, wickedness, viciousness, iniquity, peccability, demerit, sin, Adam, old Adam, offending Adam, immorality, impropriety, indecorum, scandal, laxity, looseness of morals, enphagy, dophagy, exophagy, want of principle, want of ballast, obliquity, backsliding, infamy, demoralization, pravity, depravity, pollution, hardness of heart, brutality, corruption, knavery, profligacy, flagrancy, atrocity, cannibalism, lesbianism, Sadism, infirmity, weakness, weakness of the flesh, frailty, imperfection, error, weak side, foible, failing, failure, crying sin, besetting sin, defect, deficiency, cloven foot, lowest dregs of vice, sink of iniquity, Alsatian den, gusto picaresco, fault, crime, criminality, sinner, brothel, gambling house, joint, opium den, shooting gallery, crack house, vicious, sinful, sinning, wicked, iniquitous, immoral, unrighteous, wrong, criminal, naughty, incorrect, unduteous, undutiful, unprincipled, lawless, disorderly, contra bonos mores, indecorous, unseemly, improper, dissolute, profligate, scampish, unworthy, worthless, desertless, disgraceful, recreant, reprehensible, blameworthy, uncommendable, discreditable, disreputable, Sadistic, base, sinister, scurvy, foul, gross, vile, black, grave, facinorous, felonious, nefarious, shameful, scandalous, infamous, villainous, of a deep dye, heinous, flagrant, flagitious, atrocious, incarnate, accursed, Mephistophelian, satanic, diabolic, hellish, infernal, stygian, fiendlike, hell-born, demoniacal, devilish, fiendish, miscreated, misbegotten, demoralized, corrupt, depraved, evil-minded, evil-disposed, ill-conditioned, malevolent, heartless, graceless, shameless, virtueless, abandoned, lost to virtue, unconscionable, sunk in iniquity, lost in iniquity, steeped in iniquity, incorrigible, irreclaimable, obdurate, reprobate, past praying for, culpable, reprehensible, unjustifiable, indefensible, inexcusable, inexpiable, unpardonable, irremissible, weak, frail, lax, infirm, imperfect, indiscrete, demoralizing, degrading, wrong, sinfully, without excuse, Int, O tempora!, O mores!, alitur vitium vivitque tegendo, genus est mortis male vivere, mala mens malus animus, nemo repente fuit turpissimus, the trail of the serpent is over them all, to sanction vice and hunt decorum down.For further exploring for "nefarious" in Webster Dictionary Online