Definition of nefarious in US English:

nefarious

adjective

  • (typically of an action or activity) wicked or criminal.

    ‘the nefarious activities of the organized-crime syndicates’
    • ‘Also I was told that wizards keep ghosts for their nefarious activities.’
    • ‘It is supported in its nefarious activities by a popular press acting as piranhas voraciously feeding on the shreds that remain.’
    • ‘They are the most nefarious villains of all because their purpose is never clear.’
    • ‘I know I sure wouldn't like to meet such dangerous and nefarious characters down a dark alleyway.’
    • ‘Concerned good citizens who think they may have discovered some nefarious doings should email the anti piracy team here.’
    • ‘Criminals don't carry out their nefarious acts in and around taxis.’
    • ‘She was also known for her escapades as a spy and for her various other nefarious activities.’
    • ‘Such nefarious activity sounds absurd - we are, after all, talking about the theft of objects that exist only on screen.’
    • ‘It was just a rock known for nefarious activities that took place there.’
    • ‘If you are here on a search for nefarious things, I'm afraid I have no nefarious things.’
    • ‘Al is hunting for Beta, a master criminal who makes illegal dittos of famous people for nefarious purposes.’
    • ‘All this does is make celebrities out of these crooks and encourages them to continue with their nefarious activities.’
    • ‘Through other nefarious means, the spammer has also built up a list of email addresses.’
    • ‘They haven't reckoned with the intervention of the French wine Mafia, who kidnap the kid for nefarious purposes.’
    • ‘Yet he is not cheating in the way most of us understand the term - he is not seeking to gain an advantage by nefarious means.’
    • ‘How many people were involved in nefarious activity made the journey?’
    • ‘They hit us where it hurts and do their damnedest to sell us products we neither want nor need in all manner of nefarious ways.’
    • ‘It is not a pretty wreck but its nefarious history makes it intriguing.’
    • ‘I don't know if this was because she was just trying to be unobtrusive, or if she thought we were up to some nefarious activity.’
    • ‘For that, social introspection is required at all levels to identify the root causes of such nefarious crimes.’
    wicked, evil, iniquitous, sinful, vile, foul, monstrous, shocking, outrageous, atrocious, abominable, reprehensible, hateful, detestable, despicable, odious, contemptible, horrible, heinous, execrable, diabolical, diabolic, fiendish, vicious, murderous, barbarous, black, dark, rotten
    wicked, evil, sinful, iniquitous, villainous, criminal, heinous, atrocious, appalling, abhorrent, vile, foul, base, abominable, odious, depraved, corrupt, shameful, scandalous, monstrous, fiendish, diabolical, devilish, unholy, ungodly, infernal, satanic, dark, unspeakable, despicable, outrageous, shocking, disgraceful
    View synonyms

Origin

Early 17th century: from Latin nefarius, from nefas, nefar- ‘wrong’ (from ne- ‘not’ + fas ‘divine law’) + -ous.

Pronunciation

nefarious

/nəˈferēəs//nəˈfɛriəs/