Synonyms of nefarious

nefarious

adjective

ni-ˈfer-ē-əs 

as in evil

not conforming to a high moral standard; morally unacceptable

the chaste heroines and nefarious villains of old-time melodramas

Synonyms & Similar Words

• evil
• unlawful
• immoral
• sinful
• vicious
• vile
• dark
• bad
• wicked
• villainous
• infamous
• rotten
• unethical
• corrupt
• wrong
• obscene
• iniquitous
• unsavory
• illegal
• unauthorized
• cruel
• improper
• offensive
• ugly
• unrighteous
• dirty
• nasty
• cursed
• sordid
• disreputable
• contemptible
• despicable
• ignoble
• infernal
• prohibited
• condemned
• naughty
• pernicious
• depraved
• forbidden
• reprehensible
• dishonest
• objectionable
• perverted
• atrocious
• unscrupulous
• ill
• noxious
• mean
• sick
• snide
• ungodly
• evil-minded
• unwholesome
• debauched
• unhealthy
• incorrect
• base
• censurable
• pestilential
• dissolute
• degenerate
• debased
• blameworthy
• scrofulous
• fallen
• libertine
• unseemly
• unprincipled
• loose
• proscribed
• miserable
• outlawed
• wretched
• unclean
• execrable
• barred
• dishonorable
• low-minded
• indecent
• discouraged
• errant
• low
• vulgar
• lousy
• blamable
• reprobate
• disallowed
• unbecoming
• indecorous
• erring
• cussed
• banned
• interdicted
• defiling

Antonyms & Near Antonyms

• moral
• good
• legitimate
• ethical
• honorable
• noble
• virtuous
• right
• legal
• righteous
• decent
• sublime
• high
• honest
• lofty
• scrupulous
• just
• reputable
• permissible
• upright
• permitted
• elevated
• principled
• authorized
• licensed
• endorsed
• proper
• approved
• high-minded
• sanctioned
• correct
• promoted
• allowed
• decent
• supported
• exemplary
• clean
• innocent
• pure
• perfect
• seemly
• white
• law-abiding
• decorous
• commendable
• creditable
• wholesome
• encouraged
• worthy
• blameless
• guiltless
• unobjectionable
• abetted
• venerable
• immaculate
• inoffensive
• incorruptible
• irreproachable
• spotless
• esteemed
• chaste
• uncorrupted
• respected
• unerring
• squeaky-clean
• lily-white
• unfallen
• upstanding

Synonym Chooser

How does the adjective nefarious differ from other similar words?

Some common synonyms of nefarious are corrupt, degenerate, iniquitous, vicious, and villainous. While all these words mean "highly reprehensible or offensive in character, nature, or conduct," nefarious suggests flagrant breaching of time-honored laws and traditions of conduct.

the nefarious rackets of organized crime

Where would corrupt be a reasonable alternative to nefarious?

While in some cases nearly identical to nefarious, corrupt stresses a loss of moral integrity or probity causing betrayal of principle or sworn obligations.

city hall was rife with corrupt politicians

When could degenerate be used to replace nefarious?

In some situations, the words degenerate and nefarious are roughly equivalent. However, degenerate suggests having sunk to an especially vicious or enervated condition.

a degenerate regime propped up by foreign powers

When can iniquitous be used instead of nefarious?

The words iniquitous and nefarious are synonyms, but do differ in nuance. Specifically, iniquitous implies absence of all signs of justice or fairness.

an iniquitous system of taxation

When might vicious be a better fit than nefarious?

The meanings of vicious and nefarious largely overlap; however, vicious may directly oppose virtuous in implying moral depravity, or may connote malignancy, cruelty, or destructive violence.

a vicious gangster

When would villainous be a good substitute for nefarious?

While the synonyms villainous and nefarious are close in meaning, villainous applies to any evil, depraved, or vile conduct or characteristic.

a villainous assault

Example Sentences

Recent Examples of nefarious

Bad actors like Russia’s Vladimir Putin could assign nefarious goals to an AI too. — Jason Ma, Fortune, 26 Sep. 2026

Today chaos gives bad people the opportunity to advance their own nefarious agendas with little regards for the American people. — Gary Franks, Hartford Courant, 25 Sep. 2026

Advances in the sector also increase the chance of nefarious actors launching devastating cyberattacks, with AI becoming increasingly adept at identifying and exploiting cybersecurity vulnerabilities. — Stephen Collins, The Conversation, 25 Sep. 2026

Firms like Goodfire and Apollo Research are launching products which reportedly use AI to monitor AI models for nefarious activity, according to TechCrunch. — Will McCurdy, PC Magazine, 19 Sep. 2026

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